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A 

HISTORY  OF  SCIENCE 


BY 

HENRY  SMITH  WILLIAMS,  M.D., 

LL.D. 

ASSISTED   BY 

EDWARD  H.  WILLIAMS,  M.D. 

IN    FIVE    VOLUMES 
VOLUME  I. 

THE  BEGINNINGS  OF  SCIENCE 

ILLUSTRATED 


NEW    YORK    AND 

LONDON 

HARPER     & 

BROTHERS 

PUBLISHERS 

* 

MCMIV 

1 


Copyright,  1904,  by  Harper  &  Brothers. 

All  rigkts  reserz'ed. 
Published  November,  1904. 


CONTENTS 

CHAPTER    VII 

GREEK    SCIENCE    IN    THE    EARLY    ATTIC    PERIOD 

Anaxagoras,  p.  140 — His  ideas  of  the  sun  and  stars,  and  the  origin 
of  the  heavenly  bodies,  p.  143 — His  conception  of  universal  gravi- 
tation, p.  145 — Anaxagoras  as  meteorologist,  p.  151 — His  biological 
speculations,  p.  152 — His  physical  speculations,  p.  154 — Leucippus 
and  Democritus,  p.  161 — Democritus  and  the  primordial  atom,  p. 
163 — Comparison  of  Anaxagoras  and  Democritus  as  inductive 
thinkers,  p.  163 — Hippocrates  and  Greek  medicine,  p.  170 — His 
humoral  theory  of  disease,  p.  176. 

CHAPTER    VIII 

POST-SOCRATIC    SCIENCE    AT    ATHENS 

Socrates  and  Plato,  p.  179 — Aristotle,  p.  182 — His  teachings  as  to 
the  shape  of  the  earth,  p.  183 — His  studies  in  zoology,  p.  185 — lhe 
similarity  of  his  division  of  the  animal  kingdom  to  the  Lamarckian 
system,  p.  187 — Theophrastus,  the  father  of  botany,  p.  188. 

CHAPTER    IX 

GREEK  SCIENCE  OF  THE  ALEXANDRIAN  OR  HELLENISTIC  PERIOD 

Alexandria  and  Ptolemy  Soter,  p.  189 — The  great  school  of  science 
four  ed,  p.  190 — Studies  in  geography  and  astronomy,  p.  191 — 
Euclid  and  systematic  geometry,  p.  192 — Herophilus  and  Erasistra- 
tus  and  their  studies  of  anatomy,  p.  194 — Archimedes  and  the  foun- 
dation of  mechanics,  p.  196 — His  mechanical  contrivances  for  the 
defence  of  Syracuse,  p.  201 — Plutarch's  estimate  of  Archimedes,  p. 
203 — Aristarchus  of  Samos,  p.  212 — His  anticipation  of  Copernicus 
in  his  solution  of  the  mechanism  of  the  solar  system,  p.  214 — His 
theory  of  the  revolution  of  the  earth,  p.  215 — Eratosthenes,  "the 
surveyor  of  the  world,"  p.  225 — Hipparchus,  "the  lover  of  truth," 
■a.  233 — His  measurement  of  the  length  of  the  year  and  the  moon's 
disk,  p.  239 — Ctesibus  and  Hero,  magicians  of  Alexandria,  p.  242 — 
Hero's  steam-engine  and  other  mechanical  devices,  p.   249. 

CHAPTER    X 

SCIENCE    OF   THE    ROMAN    PERIOD 

Strabo  the  geographer,  p.  255 — His  belief  in  the  globe's  sphericity, 
p.  258 — His  division  of  the  earth  into  zones,  p.  262 — Pliny  the  elder 

V 


CONTENTS 

and  Ptolemy  Secundus,  p.  265 — Natural  History  of  Pliny,  p.  266 — 
Ptolemy,  the  last  great  astronomer  of  antiquity,  p.  267 — Galen,  the 
last  great  Alexandrian,  p.  272 — His  teachings  in  anatomy,  surgery, 
arid  medicine,  p.  278 — His  conception  of  the  functions  of  the  organs 
of  the  body,  p.  282. 

CHAPTER   XI 

A    RETROSPECTIVE    GLANCE    AT    CLASSICAL    SCIENCE 

Periodicity  in  the  continuity  of  the  stream  of  history,  p.  285 — 
Length  of  the  span  from  Thales  to  Galen,  p.  286 — Retrospect  of  the 
Greek  cosmology,  p.  287 — Progress  in  the  field  of  the  biological 
sciences,  p.  288 — Birthplaces  of  the  great  philosophers  and  their 
relation  to  the  peninsula  of  Greece,  p.  289 — Racial  minglings  and 
their  bearing  upon  scientific  advancement,  p.  290 — Superstitions  of 
the  ancient  Greek  and  Roman  world,  p.  292 — An  example  of  Greek 
superstition  as  told  by  Herodotus,  p.  294— An  example  as  given  by 
Dion  Cassius,  and  the  comment  of  Xiphilinus,  p.  296. 

APPENDIX . 301 


CONTENTS 

BOOK   I 
CHAPTER    I 

PREHISTORIC    SCIENCE 

What  is  science  ?  p.  3 — Scien^fic  instincts  in  the  lower  animals,  p.  4 
— Scientific  knowledge  of  primitive  man,  p.  5 — His  observations 
of  the  sun  and  moon,  p.  7 — His  observation  of  universal  gravitation, 
p.  9 — His  observations  in  biology,  p.  11 — His  knowledge  of  medi- 
cine, p.  13 — His  conception  of  life  and  his  late  conception  of  nat- 
tiral  death,  p.  15 — His  political  ideas  and  conceptions  of  ownership, 
p.  20 — His  questionings  of  natural  phenomena  and  his  fanciful  ex- 
planations, p.  22 — His  superstitions  and  their  perpetuity  through- 
out succeeding  centuries,  p.  23. 

CHAPTER    II 

EGYPTIAN    SCIENCE 

Sources  of  our  knowledge  of  Egyptian  history,  p.  25 — Deciphering 
the  hieroglyphics,  p.  27 — State  of  civilization  at  the  beginning  of 
the  historic  period,  p.  30 — Building  the  pyramids,  p.  32 — The  dawn 
of  astronomy,  p.  33— The  Egyptian  calendar,  p.  34 — Adjustment 
of  the  calendar,  p.  35 — The  Egyptians'  ideas  of  cosmology,  p.  41 — - 
Their  scheme  of  celestial  mechanism,  p.  42 — Their  conceptions  of 
the  heavenly  bodies,  p.  44 — Charms  and  incantations,  p.  46 — 
Scientific  knowledge  of  the  Egyptian  physician,  p.  49 — Abstract 
science,  p.  51 — Methods  of  computation,  p.  52 — Science  and  super- 
stition, p.  54. 

CHAPTER    III 

SCIENCE    OF    BABYLONIA    AND    ASSYRIA. 

Babylon  in  the  time  of  Herodotus,  p.  57 — Assyrian  and  Baby- 
lonian records,,  p.  59 — Babylonian  astronomy,  p.  61 — The  adjust- 

iii 


CONTENTS 

Ynent  of  the  calendar,  p.  62 — Astrology,  p.  66 — Chaldean  magic, 
p.  69 — Various  classes  of  evil  spirits  in  different  parts  of  the  body, 
'p.  71 — The  import  of  various  omens,  p.  71 — Babylonian  medicine, 
p.  75 — Estimates  of  Babylonian  science,  p.  77 — Canon  Rawlin- 
son's  estimate,  p.  82. 


CHAPTER    IV 

THE  DEVELOPMENT  OF  THE  ALPHABET 

The  Greeklegend  of  Kadmus  and  the  introduction  of  letters,  p.  87 — 
The  Egyptian  and  Assyrian  characters,  p.  87 — First  steps  in  picture- 
writing,  p.  89 — Egyptian  writing,  p.  30 — Babylonian  writing,  p.  93 
— The  Assyrian  grammar,  p.  94 — The  alphabet  achieved,  p.  98 — 
The  extension  and  perfection  of  the   dphabet,  p.  101. 


CHAPTER    V 

THE    BEGINNINGS    OF    GREFK    SCIENCE 

Herodotus'  account  of  an  eclipse,  p.  103 — Thales,  the  Milesian,  the 
father  of  Greek  astronomy,  p.  104— His  knowledge  of  geometry, 
p.  107 — His  method  of  measuring  distant  objects,  p.  107 — Anaxi- 
mander  and  Anaximenes,  p.  109 — Anaximander's  conception  of 
the  earth,  p.  no— His  ideas  concerning  man's  development  from 
an  aquatic  animal,  p.  in. 


CHAPTER    VI 

THE    EARLY    GREEK    PHILOSOPHERS    IN    ITALY 

Pythagoras  the  boxer,  p.  112 — Pythagoras  the  philosopher,  p.  113 — ■ 
Greek  philosophers  in  Italy,  p.  114— The  followers  of  Pythagoras, 
Parmenides,  and  Empedocles,  p.  117 — The  doctrine  that  the  earth 
is  a  sphere,  p.  118 — Astronomical  observations  of  Pythagoras,  p. 
119 — His  measurements  of  triangles,  p.  120 — His  theories  accord- 
ing to  Diogenes  Laertius,  p.  121 — His  repudiation  of  the  theory  of 
spontaneous  generation,  p.  123 — Xenophanes  and  Parmenides,  p. 
127 — -Xenophanes'  conception  of  the  formation  of  fossils,  p.  12S 
— Empedocles,  physician,  observer,  and  dreamer,  p.  132 — His  de- 
nial of  an  anthropomorphic  god,  p.  134 — His  anatomical  knowl- 
edge, p.   136 — His  conception  of  evolution,  p.  137. 

iv 


ILLUSTRATIONS 


henry  smith  Williams  (Photogravure) 

MAN    AND    THE    ANTHROPOID    APES 

THE  SUN  EMBARKING  FOR  HIS  DAILY  JOURNEY  THROUGH 

EGYPT • 

TWELVE    STAGES    IN    THE    LIFE    OF    THE    SUN    AND    ITS 

TWELVE   FORMS   THROUGHOUT   THE   DAY     .... 

SHU    SEPARATING    SIBU    AND    NUIT 

'E     SELF-PROPELLING     BOAT     CONTAINING     THE     SUN, 

UNDER    THE    PROTECTION    OF    THE    TWO    EYES     . 
/HE    WORLD    AS    CONCEIVED    BY    THE    CHALDEANS        .       . 

CHALDEAN    MAP    OF    THE    WORLD 

ASSYRIAN    BAKED   CLAY  PRISMS,  WITH   INSCRIPTIONS   OF 

KINGS    SENNACHERIB    (705-681,    B.C.),    ESARHADDON 

(681-66S,  B.C.),  AND    ASHUR-BANI-PAL  (668-626,   B.C.) 

THE    MOABITE    STONE 

MEXICAN    PICTURE-WRITING 

REPRODUCTION  OF  A  FRAGMENT  OF  THE  EGYPTIAN  BOOK 

OF    THE    DEAD 

OLD    BABYLONIAN    INSCRIPTION 

PYTHAGORAS 

HIPPOCRATES        

ARISTOTLE 

ARCHIMEDES 

vii 


Frontispiece 
Facing  p.      10 

36 

40 
"     42 

46 
62 
64 


68 
86 


90 

96 

114 

170 

182 


ILLUSTRATIONS 


DIAGRAM  TO   ILLUSTRATE  ARISTARCHUS     MEASUREMENT 
OF  THE  RELATIVE   DISTANCES   FROM  THE  EARTH  OF 

THE    MOON    AND    THE    SUN Facing  p.    2l8 

DIAGRAM     TO     ILLUSTRATE     ERATOSTHENES*     MEASURE- 
MENT   OF    THE    GLOBE "  230 

DEVICE    FOR    CAUSING    THE    DOORS    OF    THE    TEMPLE    TO 

OPEN   WHEN   THE   FIRE   ON    THE  ALTAR   IS    LIGHTED  "  246 

THE    STEAM-ENGINE    OF    HERO "  24S 

THE    SLOT-MACHINE    OF    HERO "  250 

PLINY ' "  254 

PTOLEMY "  268 

GALEN "  280 


A   HISTORY  OF  SCIENCE 
BOOK  I 

SHOULD  the  story  that  is  about  to  be  unfolded 
be  found  to  lack  interest,  the  writers  must  stand 
convicted  of  unpardonable  lack  of  art.  Nothing  but 
dulness  in  the  telling  could  mar  the  story,  for  in  itself 
it  is  the  record  of  the  growth  of  those  ideas  that  have 
made  our  race  and  its  civilization  what  they  are;  of 
ideas  instinct  with  human  interest,  vital  with  meaning 
for  our  race ;  fundamental  in  their  influence  on  human 
development;  part  and  parcel  of  the  mechanism  of 
human  thought  on  the  one  hand,  and  of  practical  civil- 
ization on  the  other.  Such  a  phrase  as  "  fundamental 
principles ' '  may  seem  at  first  thought  a  hard  saying, 
but  the  idea  it  implies  is  less  repellent  than  the  phrase 
itself,  for  the  fundamental  principles  in  question  are 
so  closely  linked  with  the  present  interests  of  every  one 
of  us  that  they  lie  within  the  grasp  of  every  average 
man  and  woman — nay,  of  every  well-developed  boy 
and  girl.  These  principles  are  not  merely  the  stepping- 
stones  to  culture,   the  prerequisites  of  knowledge — 

i 


A   HISTORY   OF   SCIENCE 

they  are,  in  themselves,  an  essential  part  of  the  knowl- 
edge of  every  cultivated  person. 

It  is  our  task,  not  merely  to  show  what  these  prin- 
ciples are,  but  to  point  out  how  they  have  been  dis- 
covered by  our  predecessors.  We  shall  trace  the 
growth  of  these  ideas  from  their  first  vague  beginnings. 
We  shall  see  how  vagueness  of  thought  gave  way  to 
precision;  how  a  general  truth,  once  grasped  and 
formulated,  was  found  to  be  a  stepping-stone  to  other 
truths.  We  shall  see  that  there  are  no  isolated  facts, 
no  isolated  principles,  in  nature ;  that  each  part  of  our 
story  is  linked  by  indissoluble  bands  with  that  which 
goes  before,  and  with  that  which  comes  after.  For 
the  most  part  the  discovery  of  this  principle  or  that  in 
a  given  sequence  is  no  accident.  Galileo  and  Keppler 
must  precede  Newton.  Cuvier  and  Lyall  must  come 
before  Darwin ; — which,  after  all,  is  no  more  than  say- 
ing that  in  our  Temple  of  Science,  as  in  any  other  piece 
of  architecture,  the  foundation  must  precede  the  super- 
structure. 

We  shall  best  understand  our  story  of  the  growth 
of  science  if  we  think  of  each  new  principle  as  a  step- 
ping-stone which  must  fit  into  its  own  particular 
niche;  and  if  we  reflect  that  the  entire  structure  of 
modern  civilization  would  be  different  from  what  it  is, 
and  less  perfect  than  it  is,  had  not  that  particular 
stepping-stone  been  found  and  shaped  and  placed  in 
position.  Taken  as  a  whole,  our  stepping-stones  lead 
us  up  and  up  towards  the  alluring  heights  of  an  acrop- 
olis of  knowledge,  on  which  stands  the  Temple  of  Mod- 
ern Science.  The  story  of  the  building  of  this  wonder- 
ful structure  is  in  itself  fascinating  and  beautiful. 


PREHISTORIC  SCIENCE 

TO  speak  of  a  prehistoric  science  may  seem  like 
a  contradiction  of  terms.  The  word  prehistoric 
seems  to  imply  barbarism,  while  science,  clearly 
enough,  seems  the  outgrowth  of  civilization;  but 
rightly  considered,  there  is  no  contradiction.  For, 
on  the  one  hand,  man  had  ceased  to  be  a  barbarian 
long  before  the  beginning  of  what  we  call  the  historical 
period;  and,  on  the  other  hand,  science,  of  a  kind,  is 
no  less  a  precursor  and  a  cause  of  civilization  than  it 
is  a  consequent.  To  get  this  clearly  in  mind,  we  must 
ask  ourselves:  What,  then,  is  science?  The  word 
runs  glibly  enough  upon  the  tongue  of  our  every -day 
speech,  but  it  is  not  often,  perhaps,  that  they  who  use 
it  habitually  ask  themselves  just  what  it  means.  Yet 
the  answer  is  not  difficult.  A  little  attention  will 
show  that  science,  as  the  word  is  commonly  used, 
implies  these  things:  first,  the  gathering  of  knowledge 
through  observation;  second,  the  classification  of  such 
knowledge,  and  through  this  classification,  the  elabo- 
ration of  general  ideas  or  principles.  In  the  familiar 
definition  of  Herbert  Spencer,  science  is  organized 
knowledge. 

Now  it  is  patent  enough,  at  first  glance,  that  the 
veriest  savage  must  have  been  an  observer  of  the 
phenomena  of  nature.     But  it  may  not  be  so  obvious 

3 


A   HISTORY   OF   SCIENCE 

that  he  must  also  have  been  a  classifier  of  his  ob- 
servations— an  organizer  of  knowledge.  Yet  the  more 
we  consider  the  case,  the  more  clear  it  will  become  that 
the  two  methods  are  too  closely  linked  together  to 
be  dissevered.  To  observe  outside  phenomena  is  not 
more  inherent  in  the  nature  of  the  mind  than  to  draw 
inferences  from  these  phenomena.  A  deer  passing 
through  the  forest  scents  the  ground  and  detects  a 
certain  odor.  A  sequence  of  ideas  is  generated  in 
the  mind  of  the  deer.  Nothing  in  the  deer's  experience 
can  produce  that  odor  but  a  wolf ;  therefore  the  scien- 
tific inference  is  drawn  that  wolves  have  passed  that 
way.  But  it  is  a  part  of  the  deer's  scientific  knowledge, 
based  on  previous  experience,  individual  and  racial, 
that  wolves  are  dangerous  beasts,  and  so,  combining 
direct  observation  in  the  present  with  the  application 
of  a  general  principle  based  on  past  experience,  the 
deer  reaches  the  very  logical  conclusion  that  it  may 
wisely  turn  about  and  run  in  another  direction.  All 
this  implies,  essentially,  a  comprehension  and  use  of 
scientific  principles;  and,  strange  as  it  seems  to  speak 
of  a  deer  as  possessing  scientific  knowledge,  yet  there 
is  really  no  absurdity  in  the  statement.  The  deer 
does  possess  scientific  knowledge;  knowledge  differing 
in  degree  only,  not  in  kind,  from  the  knowledge  of  a 
Newton.  Nor  is  the  animal,  within  the  range  of  its 
intelligence,  less  logical,  less  scientific  in  the  application 
of  that  knowledge,  than  is  the  man.  The  animal  that 
could  not  make  accurate  scientific  observations  of  its 
suiToundings,  and  deduce  accurate  scientific  conclu- 
sions from  them,  would  soon  pay  the  penalty  of  its  lack 
of  logic, 

4 


PREHISTORIC   SCIENCE 

What  is  true  of  man's  precursors  in  the  animal  scale 
is,  of  course,  true  in  a  wider  and  fuller  sense  of  man  him- 
self at  the  very  lowest  stage  of  his  development.  Ages 
before  the  time  which  the  limitations  of  our  knowledge 
force  us  to  speak  of  as  the  dawn  of  history,  man  had 
reached  a  high  stage  of  development.  As  a  social 
being,  he  had  developed  all  the  elements  of  a  primitive 
civilization.  If,  for  convenience  of  classification,  we 
speak  of  his  state  as  savage,  or  barbaric,  we  use  terms 
which,  after  all,  are  relative,  and  which  do  not  shut 
off  our  primitive  ancestors  from  a  tolerably  close  asso- 
ciation with  our  own  ideals.  We  know  that,  even  in 
the  Stone  Age,  man  had  learned  how  to  domesticate 
animals  and  make  them  useful  to  him,  and  that  he  had 
also  learned  to  cultivate  the  soil.  Later  on,  doubtless 
by  slow  and  painful  stages,  he  attained  those  wonder- 
ful elements  of  knowledge  that  enabled  him  to  smelt 
metals  and  to  produce  implements  of  bronze,  and  then 
of  iron.  Even  in  the  Stone  Age  he  was  a  mechanic  of 
marvellous  skill,  as  any  one  of  to-day  may  satisfy  him- 
self by  attempting  to  duplicate  such  an  implement  as 
a  chipped  arrow-head.  And  a  barbarian  who  could 
fashion  an  axe  or  a  knife  of  bronze  had  certainly  gone 
far  in  his  knowledge  of  scientific  principles  and  their 
practical  application.  The  practical  application  was, 
doubtless,  the  only  thought  that  our  primitive  an- 
cestor had  in  mind;  quite  probably  the  question  as 
to  principles  that  might  be  involved  troubled  him  not 
at  all.  Yet,  in  spite  of  himself,  he  knew  certain  rudi- 
mentary principles  of  science,  even  though  he  did  not 
formulate  them. 

Let  us  inquire  what  some  of  these  principles  are. 

5 


A   HISTORY   OF   SCIENCE 

Such  an  inquiry  will,  as  it  were,  clear  the  ground  for 
our  structure  of  science.  It  will  show  the  plane  of 
knowledge  on  which  historical  investigation  begins. 
Incidentally,  perhaps,  it  will  reveal  to  us  unsuspected 
affinities  between  ourselves  and  our  remote  ancestor. 
Without  attempting  anything  like  a  full  analysis,  we 
may  note  in  passing,  not  merely  what  primitive  man 
knew,  but  what  he  did  not  know ;  that  at  least  a  vague 
notion  may  be  gained  of  the  field  for  scientific  research 
that  lay  open  for  historic  man  to  cultivate. 

It  must  be  understood  that  the  knowledge  of  primi- 
tive man,  as  we  are  about  to  outline  it,  is  inferential. 
We  cannot  trace  the  development  of  these  principles, 
much  less  can  we  say  who  discovered  them.  Some  of 
them,  as  already  suggested,  are  man's  heritage  from 
non-human  ancestors.  Others  can  only  have  been 
grasped  by  him  after  he  had  reached  a  relatively  high 
stage  of  human  development.  But  all  the  principles 
here  listed  must  surely  have  been  parts  of  our  primi- 
tive ancestor's  knowledge  before  those  earliest  days  of 
Egyptian  and  Babylonian  civilization,  the  records  of 
which  constitute  our  first  introduction  to  the  so-called 
historical  period.  Taken  somewhat  in  the  order  of 
their  probable  discovery,  the  scientific  ideas  of  primi- 
tive man  may  be  roughly  listed  as  follows : 

i.  Primitive  man  must  have  conceived  that  the 
earth  is  flat  and  of  limitless  extent.  By  this  it  is  not 
meant  to  imply  that  he  had  a  distinct  conception  of 
infinity,  but,  for  that  matter,  it  cannot  be  said  that 
any  one  to-day  has  a  conception  of  infinity  that  could 
be  called  definite.     But,   reasoning  from  experience 

6 


PREHISTORIC   SCIENCE 

and  the  reports  of  travellers,  there  was  nothing  to  sug- 
gest to  early  man  the  limit  of  the  earth.  He  did,  in- 
deed, find  in  his  wanderings,  that  changed  climatic  con- 
ditions barred  him  from  farther  progress;  but  beyond 
the  farthest  reaches  of  his  migrations,  the  seemingly 
flat  land-surfaces  and  water-surfaces  stretched  away 
unbroken  and,  to  all  appearances,  without  end.  It 
would  require  a  reach  of  the  philosophical  imagination 
to  conceive  a  limit  to  the  earth,  and  while  such  imag- 
inings may  have  been  current  in  the  prehistoric  period, 
we  can  have  no  proof  of  them,  and  we  may  well  post- 
pone consideration  of  man's  early  dreamings  as  to  the 
shape  of  the  earth  until  we  enter  the  historical  epoch 
where  we  stand  on  firm  ground. 

2.  Primitive  man  must,  from  a  very  early  period, 
have  observed  that  the  sun  gives  heat  and  light,  and 
that  the  moon  and  stars  seem  to  give  light  only  and 
no  heat.  It  required  but  a  slight  extension  of  this 
observation  to  note  that  the  changing  phases  of  the 
seasons  were  associated  with  the  seeming  approach  and 
recession  of  the  sun.  This  observation,  however, 
could  not  have  been  made  until  man  had  migrated 
from  the  tropical  regions,  and  had  reached  a  stage  of 
mechanical  development  enabling  him  to  live  in  sub- 
tropical or  temperate  zones.  Even  then  it  is  con- 
ceivable that  a  long  period  must  have  elapsed  before  a 
direct  causal  relation  was  felt  to  exist  between  the 
shifting  of  the  sun  and  the  shifting  of  the  seasons; 
because,  as  every  one  knows,  the  periods  of  greatest 
heat  in  summer  and  greatest  cold  in  winter  usually 
come  some  weeks  after  the  time  of  the  solstices.  Yet, 
the  fact  that  these  extremes  of  temperature  are  asso- 

7 


A   HISTORY   OF   SCIENCE 

ciated  in  some  way  with  the  change  of  the  sun's  place 
in  the  heavens  must,  in  time,  have  impressed  itself 
upon  even  a  rudimentary  intelligence.  It  is  hardly 
necessary  to  add  that  this  is  not  meant  to  imply  any 
definite  knowledge  of  the  real  meaning  of  the  seeming 
oscillations  of  the  sun.  We  shall  see  that,  even  at 
a  relatively  late  period,  the  vaguest  notions  were 
still  in  vogue  as  to  the  cause  of  the  sun's  changes  of 
position. 

That  the  sun,  moon,  and  stars  move  across  the 
heavens  must  obviously  have  been  among  the  earliest 
scientific  observations.  It  must  not  be  inferred,  how- 
ever, that  this  observation  implied  a  necessary  con- 
ception of  the  complete  revolution  of  these  bodies  about 
the  earth.  It  is  unnecessary  to  speculate  here  as  to 
how  the  primitive  intelligence  conceived  the  transfer 
of  the  sun  from  the  western  to  the  eastern  horizon,  to 
be  effected  each  night,  for  we  shall  have  occasion  to 
examine  some  historical  speculations  regarding  this 
phenomenon.  We  may  assume,  however,  that  the 
idea  of  the  transfer  of  the  heavenly  bodies  beneath  the 
earth  (whatever  the  conception  as  to  the  form  of  that 
body)  must  early  have  presented  itself. 

It  required  a  relatively  high  development  of  the  ob- 
serving faculties,  yet  a  development  which  man  must 
have  attained  ages  before  the  historical  period,  to  note 
that  the  moon  has  a  secondary  motion,  which  leads  it 
to  shift  its  relative  position  in  the  heavens,  as  regards 
the  stars ;  that  the  stars  themselves,  on  the  other  hand, 
keep  a  fixed  relation  as  regards  one  another,  with  the 
notable  exception  of  two  or  three  of  the  most  brilliant 
members  of  the  galaxy,  the  latter  being  the  bodies 


PREHISTORIC   SCIENCE 

which  came  to  be  known  finally  as  planets,  or  wander- 
ing stars.  The  wandering  propensities  of  such  brilliant 
bodies  as  Jupiter  and  Venus  cannot  well  have  escaped 
detection.  We  may  safely  assume,  however,  that  these 
anomalous  motions  of  the  moon  and  planets  found  no 
explanation  that  could  be  called  scientific  until  a  rela- 
tively late  period. 

3.  Turning  from  the  heavens  to  the  earth,  and  ig- 
noring such  primitive  observations  as  that  of  the  dis- 
tinction between  land  and  water,  we  may  note  that 
there  was  one  great  scientific  law  which  must  have 
forced  itself  upon  the  attention  of  primitive  man. 
This  is  the  law  of  universal  terrestrial  gravitation.  The 
word  gravitation  suggests  the  name  of  Newton,  and  it 
may  excite  surprise  to  hear  a  knowledge  of  gravitation 
ascribed  to  men  who  preceded  that  philosopher  by,  say, 
twenty -five  or  fifty  thousand  years.  Yet  the  slightest 
consideration  of  the  facts  will  make  it  clear  that  the 
great  central  law  that  all  heavy  bodies  fall  directly 
towards  the  earth,  cannot  have  escaped  the  attention 
of  the  most  primitive  intelligence.  The  arboreal 
habits  of  our  primitive  ancestors  gave  opportunities 
for  constant  observation  of  the  practicalities  of  this 
law.  And,  so  soon  as  man  had  developed  the  mental 
capacity  to  formulate  ideas,  one  of  the  earliest  ideas 
must  have  been  the  conception,  however  vaguely 
phrased  in  words,  that  all  unsupported  bodies  fall  tow- 
ards the  earth.  The  same  phenomenon  being  observed 
to  operate  on  water-surfaces,  and  no  alteration  being 
observed  in  its  operation  in  different  portions  of  man's 
habitat,  the  most  primitive  wanderer  must  have  come 
to  have  full  faith  in  the  universal  action  of  the  ob- 

9 


A   HISTORY    OF  SCIENCE 

served  law  of  gravitation.  Indeed,  it  is  inconceivable 
that  he  can  have  imagined  a  place  on  the  earth  where 
this  law  does  not  operate.  On  the  other  hand,  of 
course,  he  never  grasped  the  conception  of  the  opera- 
tion of  this  law  beyond  the  close  proximity  of  the 
earth.  To  extend  the  reach  of  gravitation  out  to  the 
moon  and  to  the  stars,  including  within  its  compass 
every  particle  of  matter  in  the  universe,  was  the  work 
of  Newton,  as  we  shall  see  in  due  course.  Meantime 
we  shall  better  understand  that  work  if  we  recall  that 
the  mere  local  fact  of  terrestrial  gravitation  has  been 
the  familiar  knowledge  of  all  generations  of  men.  It 
may  further  help  to  connect  us  in  sympathy  with  our 
primeval  ancestor  if  we  recall  that  in  the  attempt  to 
explain  this  fact  of  terrestrial  gravitation  Newton 
made  no  advance,  and  we  of  to-day  are  scarcely  more 
enlightened  than  the  man  of  the  Stone  Age.  Like 
the  man  of  the  Stone  Age,  we  know  that  an  arrow 
shot  into  the  sky  falls  back  to  the  earth.  We  can 
calculate,  as  he  could  not  do,  the  arc  it  will  de- 
scribe and  the  exact  speed  of  its  fall;  but  as  to  why 
it  returns  to  earth  at  all,  the  greatest  philosopher 
of  to-day  is  almost  as  much  in  the  dark  as  was 
the  first  primitive  bowman  that  ever  made  the  ex- 
periment. 

Other  physical  facts  going  to  make  up  an  elementary 
science  of  mechanics,  that  were  demonstratively  known 
to  prehistoric  man,  were  such  as  these :  the  rigidity  of 
solids  and  the  mobility  of  liquids ;  the  fact  that  changes 
of  temperature  transform  solids  to  liquids  and  vice 
versa — that  heat,  for  example,  melts  copper  and  even 
iron,  and  that  cold  congeals  water;  and  the  fact  that 

10 


TO  << 

5-' -2 


|>  o> 


> 

8-  3 

3     w 


PREHISTORIC   SCIENCE 

friction,  as  illustrated  in  the  rubbing  together  of  two 
sticks,  may  produce  heat  enough  to  cause  afire.  The 
rationale  of  this  last  experiment  did  not  receive  an 
explanation  until  about  the  beginning  of  the  nineteenth 
century  of  our  own  era.  But  the  experimental  fact 
was  so  well  known  to  prehistoric  man  that  he  employed 
this  method,  as  various  savage  tribes  employ  it  to  this 
day,  for  the  altogether  practical  purpose  of  making  a 
fire ;  just  as  he  employed  his  practical  knowledge  of  the 
mutability  of  solids  and  liquids  in  smelting  ores,  in 
alloying  copper  with  tin  to  make  bronze,  and  in  casting 
this  alloy  in  molds  to  make  various  implements  and 
weapons.  Here,  then,  were  the  germs  of  an  elementary 
science  of  physics.  Meanwhile  such  observations  as 
that  of  the  solution  of  salt  in  water  may  be  considered 
as  giving  a  first  lesson  in  chemistry,  but  beyond  such 
altogether  rudimentary  conceptions  chemical  knowl- 
edge could  not  have  gone — unless,  indeed,  the  prac- 
tical observation  of  the  effects  of  fire  be  included ;  nor 
can  this  well  be  overlooked,  since  scarcely  another 
single  line  of  practical  observation  had  a  more  direct 
influence  in  promoting  the  progress  of  man  towards 
the  heights  of  civilization. 

4.  In  the  field  of  what  we  now  speak  of  as  biological 
knowledge,  primitive  man  had  obviously  the  widest 
opportunity  for  practical  observation.  We  can  hardly 
doubt  that  man  attained,  at  an  early  day,  to  that  con- 
ception of  identity  and  of  difference  which  Plato  places 
at  the  head  of  his  metaphysical  system.  We  shall  urge 
presently  that  it  is  precisely  such  general  ideas  as  these 
that  were  man's  earliest  inductions  from  observation, 
and  hence  that  came  to  seem  the  most  universal  and 

11 


A   HISTORY   OF   SCIENCE 

"  innate  "  ideas  of  his  mentality.  It  is  quite  inconceiv- 
able, for  example,  that  even  the  most  rudimentary 
intelligence  that  could  be  called  human  could  fail  to 
discriminate  between  living  things  and,  let  us  say, 
the  rocks  of  the  earth.  The  most  primitive  intelli- 
gence, then,  must  have  made  a  tacit  classification  of 
the  natural  objects  about  it  into  the  grand  divisions 
of  animate  and  inanimate  nature.  Doubtless  the  nas- 
cent scientist  may  have  imagined  life  animating  many 
bodies  that  we  should  call  inanimate — such  as  the  sun, 
wandering  planets,  the  winds,  and  lightning;  and,  on 
the  other  hand,  he  may  quite  likely  have  relegated 
such  objects  as  trees  to  the  ranks  of  the  non-living ;  but 
that  he  recognized  a  fundamental  distinction  between, 
let  us  say,  a  wolf  and  a  granite  bowlder  we  cannot  well 
doubt.  A  step  beyond  this  —  a  step,  however,  that 
may  have  required  centuries  or  millenniums  in  the 
taking — must  have  carried  man  to  a  plane  of  intelli- 
gence from  which  a  primitive  Aristotle  or  Linnagus  was 
enabled  to  note  differences  and  resemblances  connoting 
such  groups  of  things  as  fishes,  birds,  and  furry  beasts. 
This  conception,  to  be  sure,  is  an  abstraction  of  a  rela- 
tively high  order.  We  know  that  there  are  savage 
races  to  -  day  whose  language  contains  no  word  for 
such  an  abstraction  as  bird  or  tree.  We  are  bound  to 
believe,  then,  that  there  were  long  ages  of  human 
progress  during  which  the  highest  man  had  attained 
no  such  stage  of  abstraction;  but,  on  the  other  hand, 
it  is  equally  little  in  question  that  this  degree  of  mental 
development  had  been  attained  long  before  the  opening 
of  our  historical  period.  The  primeval  man,  then, 
whose  scientific  knowledge  we  are  attempting  to  predi- 

12 


PREHISTORIC   SCIENCE 

cate,  had  become,  through  his  conception  of  fishes, 
birds,  and  hairy  animals  as  separate  classes,  a  scientific 
zoologist  of  relatively  high  attainments. 

In  the  practical  field  of  medical  knowledge,  a  certain 
stage  of  development  must  have  been  reached  at  a  very 
early  day.  Even  animals  pick  and  choose  among  the 
vegetables  about  them,  and  at  times  seek  out  certain 
herbs  quite  different  from  their  ordinary  food,  prac- 
tising a  sort  of  instinctive  therapeutics.  The  cat's 
fondness  for  catnip  is  a  case  in  point.  The  most  primi- 
tive man,  then,  must  have  inherited  a  racial  or  instinc- 
tive knowledge  of  the  medicinal  effects  of  certain  herbs ; 
in  particular  he  must  have  had  such  elementary  knowl- 
edge of  toxicology  as  would  enable  him  to  avoid  eating 
certain  poisonous  berries.  Perhaps,  indeed,  we  are 
placing  the  effect  before  the  cause  to  some  extent ;  for, 
after  all,  the  animal  system  possesses  marvellous  pow- 
ers of  adaption,  and  there  is  perhaps  hardly  any  poison- 
ous vegetable  which  man  might  not  have  learned  to 
eat  without  deleterious  effect,  provided  the  experi- 
ment were  made  gradually.  To  a  certain  extent,  then, 
the  observed  poisonous  effects  of  numerous  plants 
upon  the  human  system  are  to  be  explained  by  the 
fact  that  our  ancestors  have  avoided  this  particular 
vegetable.  Certain  fruits  and  berries  might  have  come 
to  have  been  a  part  of  man's  diet,  had  they  grown  in 
the  regions  he  inhabited  at  an  early  day,  which  now 
are  poisonous  to  his  system.  This  thought,  however, 
carries  us  too  far  afield.  For  practical  purposes,  it  suf- 
fices that  certain  roots,  leaves,  and  fruits  possess  prin- 
ciples that  are  poisonous  to  the  human  system,  and 
that  unless  man  had  learned  in  some  way  to  avoid 

i3 


A   HISTORY   OF  SCIENCE 

these,  our  race  must  have  come  to  disaster.  In  point 
of  fact,  he  did  learn  to  avoid  them;  and  such  evi- 
dence implied,  as  has  been  said,  an  elementary  knowl- 
edge of  toxicology. 

Coupled  with  this  knowledge  of  things  dangerous  to 
the  human  system,  there  must  have  grown  up,  at  a 
very  early  day,  a  belief  in  the  remedial  character  of 
various  vegetables  as  agents  to  combat  disease.  Here, 
of  course,  was  a  rudimentary  therapeutics,  a  crude 
principle  of  an  empirical  art  of  medicine.  As  just  sug- 
gested, the  lower  order  of  animals  have  an  instinctive 
knowledge  that  enables  them  to  seek  out  remedial 
herbs  (though  we  probably  exaggerate  the  extent  of 
this  instinctive  knowledge) ;  and  if  this  be  true,  man 
must  have  inherited  from  his  prehuman  ancestors  this 
instinct  along  with  the  others.  That  he  extended  this 
knowledge  through  observation  and  practice,  and  came 
early  to  make  extensive  use  of  drugs  in  the  treatment 
of  disease,  is  placed  beyond  cavil  through  the  obser- 
vation of  the  various  existing  barbaric  tribes,  nearly 
all  of  whom  practice  elaborate  systems  of  therapeutics. 
We  shall  have  occasion  to  see  that  even  within  his- 
toric times  the  particular  therapeutic  measures  em- 
ployed were  often  crude,  and,  as  we  are  accustomed 
to  say,  unscientific;  but  even  the  crudest  of  them 
are  really  based  upon  scientific  principles,  inasmuch 
as  their  application  implies  the  deduction  of  prin- 
ciples of  action  from  previous  observations.  Certain 
drugs  are  applied  to  appease  certain  symptoms  of 
disease  because  in  the  belief  of  the  medicine -man 
such  drugs  have  proved  beneficial  in  previous  similar 
cases. 

14 


PREHISTORIC   SCIENCE 

All  this,  however,  implies  an  appreciation  of  the  fact 
that  man  is  subject  to  "natural"  diseases,  and  that  if 
these  diseases  are  not  combated,  death  may  result. 
But  it  should  be  understood  that  the  earliest  man  prob- 
ably had  no  such  conception  as  this.  Throughout  all 
the  ages  of  early  development,  what  we  call  "natural" 
disease  and  "natural  "  death  meant  the  onslaught  of  a 
tangible  enemy.  A  study  of  this  question  leads  us 
to  some  very  curious  inferences.  The  more  we  look 
into  the  matter  the  more  the  thought  forces  itself  home 
to  us  that  the  idea  of  natural  death,  as  we  now  con- 
ceive it,  came  to  primitive  man  as  a  relatively  late 
scientific  induction.  This  thought  seems  almost  star- 
tling, so  axiomatic  has  the  conception  "man  is  mortal" 
come  to  appear.  Yet  a  study  of  the  ideas  of  existing 
savages,  combined  with  our  knowledge  of  the  point  of 
view  from  which  historical  peoples  regard  disease, 
make  it  more  probable  that  the  primitive  conception 
of  human  life  did  not  include  the  idea  of  necessary 
death.  We  are  told  that  the  Australian  savage  who 
falls  from  a  tree  and  breaks  his  neck  is  not  regarded  as 
having  met  a  natural  death,  but  as  having  been  the 
victim  of  the  magical  practices  of  the  "medicine-man" 
of  some  neighboring  tribe.  Similarly,  we  shall  find 
that  the  Egyptian  and  the  Babylonian  of  the  early 
historical  period  conceived  illness  as  being  almost  in- 
variably the  result  of  the  machinations  of  an  enemy. 
One  need  but  recall  the  superstitious  observances  of 
the  Middle  Ages,  and  the  yet  more  recent  belief  in 
witchcraft,  to  realize  how  generally  disease  has  been 
personified  as  a  malicious  agent  invoked  by  an  un- 
friendly mind.     Indeed,  the  phraseology  of  our  pres- 

15 


A   HISTORY    OF   SCIENCE 

ent-day  speech  is  still  reminiscent  of  this ;  as  when,  for 
example,  we  speak  of  an  "attack  of  fever,"  and  the 
like. 

When,  following  out  this  idea,  we  picture  to  our- 
selves the  conditions  under  which  primitive  man  lived, 
it  will  be  evident  at  once  how  relatively  infrequent 
must  have  been  his  observation  of  what  we  usually 
term  natural  death.  His  world  was  a  world  of  strife ; 
he  lived  by  the  chase ;  he  saw  animals  kill  one  another ; 
he  witnessed  the  death  of  his  own  fellows  at  the  hands 
of  enemies.  Naturally  enough,  then,  when  a  member 
of  his  family  was  "struck  down"  by  invisible  agents, 
he  ascribed  this  death  also  to  violence,  even  though 
the  offensive  agent  was  concealed.  Moreover,  having 
very  little  idea  of  the  lapse  of  time — being  quite  un- 
accustomed, that  is,  to  reckon  events  from  any  fixed 
era — primitive  man  cannot  have  gained  at  once  a  clear 
conception  of  age  as  applied  to  his  fellows.  Until  a 
relatively  late  stage  of  development  made  tribal  life 
possible,  it  cannot  have  been  usual  for  man  to  have 
knowledge  of  his  grandparents;  as  a  rule  he  did  not 
know  his  own  parents  after  he  had  passed  the  adolescent 
stage  and  had  been  turned  out  upon  the  world  to  care 
for  himself.  If,  then,  certain  of  his  fellow  -  beings 
showed  those  evidences  of  infirmity  which  we  ascribe 
to  age,  it  did  not  necessarily  follow  that  he  saw  any 
association  between  such  infirmities  and  the  length  of 
time  which  those  persons  had  lived.  The  very  fact 
that  some  barbaric  nations  retain  the  custom  of  killing 
the  aged  and  infirm,  in  itself  suggests  the  possibility 
that  this  custom  arose  before  a  clear  conception  had 
been  attained  that  such  drags  upon  the  community 

16 


PREHISTORIC   SCIENCE 

would  be  removed  presently  in  the  natural  order  of 
things.  To  a  person  who  had  no  clear  conception  of 
the  lapse  of  time  and  no  preconception  as  to  the  limited 
period  of  man's  life,  the  infirmities  of  age  might  very 
naturally  be  ascribed  to  the  repeated  attacks  of  those 
inimical  powers  which  were  understood  sooner  or  later 
to  carry  off  most  members  of  the  race.  And  coupled 
with  this  thought  would  go  the  conception  that  inas- 
much as  some  people  through  luck  had  escaped  the 
vengeance  of  all  their  enemies  for  long  periods,  these 
same  individuals  might  continue  to  escape  for  indefinite 
periods  of  the  future.  There  were  no  written  records 
to  tell  primeval  man  of  events  of  long  ago.  He  lived 
in  the  present,  and  his  sweep  of  ideas  scarcely  carried 
him  back  beyond  the  limits  of  his  individual  memory. 
But  memory  is  observed  to  be  fallacious.  It  must  early 
have  been  noted  that  some  people  recalled  events  which 
other  participants  in  them  had  quite  forgotten,  and 
it  may  readily  enough  have  been  inferred  that  those 
members  of  the  tribe  who  spoke  of  events  which  others 
could  not  recall  were  merely  the  ones  who  were  gifted 
with  the  best  memories.  If  these  reached  a  period 
when  their  memories  became  vague,  it  did  not  follow 
that  their  recollections  had  carried  them  back  to  the 
beginnings  of  their  lives.  Indeed,  it  is  contrary  to  all 
experience  to  believe  that  any  man  remembers  all 
the  things  he  has  once  known,  and  the  observed  falla- 
ciousness and  evanescence  of  memory  would  thus  tend 
to  substantiate  rather  than  to  controvert  the  idea  that 
various  members  of  a  tribe  had  been  alive  for  an  in- 
definite period. 

Without  further  elaborating  the  argument,  it  seems 

VOL.    I. 2  17 


A   HISTORY    OF   SCIENCE 

a  justifiable  inference  that  the  first  conception  primi- 
tive man  would  have  of  his  own  life  would  not  include 
the  thought  of  natural  death,  but  would,  conversely, 
connote  the  vague  conception  of  endless  life.  Our  own 
ancestors,  a  few  generations  removed,  had  not  got  rid 
of  this  conception,  as  the  perpetual  quest  of  the  spring 
of  eternal  youth  amply  testifies.  A  naturalist  of  our 
own  day  has  suggested  that  perhaps  birds  never  die 
except  by  violence.  The  thought,  then,  that  man  has  a 
term  of  years  beyond  which  "in  the  nature  of  things," 
as  the  saying  goes,  he  may  not  live,  would  have  dawned 
but  gradually  upon  the  developing  intelligence  of  suc- 
cessive generations  of  men;  and  we  cannot  feel  sure 
that  he  would  fully  have  grasped  the  conception  of  a 
"natural"  termination  of  human  life  until  he  had 
shaken  himself  free  from  the  idea  that  disease  is  always 
the  result  of  the  magic  practice  of  an  enemy.  Our 
observation  of  historical  man  in  antiquity  makes  it 
somewhat  doubtful  whether  this  conception  had  been 
attained  before  the  close  of  the  prehistoric  period.  If 
it  had,  this  conception  of  the  mortality  of  man  was  one 
of  the  most  striking  scientific  inductions  to  which  pre- 
historic man  attained.  Incidentally,  it  may  be  noted 
that  the  conception  of  eternal  life  for  the  human  body 
being  a  more  primitive  idea  than  the  conception  of 
natural  death,  the  idea  of  the  immortality  of  the  spirit 
would  be  the  most  natural  of  conceptions.  The  im- 
mortal spirit,  indeed,  would  be  but  a  correlative  of  the 
immortal  body,  and  the  idea  which  we  shall  see  preva- 
lent among  the  Egyptians  that  the  soul  persists  only 
as  long  as  the  body  is  intact — the  idea  upon  which  the 
practice  of  mummifying  the  dead  depended — finds  a 

18 


PREHISTORIC   SCIENCE 

ready  explanation.  But  this  phase  of  the  subjecij 
carries  us  somewhat  afield.  For  our  present  purpose 
it  suffices  to  have  pointed  out  that  the  conception  of 
man's  mortality — a  conception  which  now  seems  of  all 
others  the  most  natural  and  "innate" — was  in  all 
probability  a  relatively  late  scientific  induction  of  our 
primitive  ancestors. 

5.  Turning  from  the  consideration  of  the  body  to 
its  mental  complement,  we  are  forced  to  admit  that 
here,  also,  our  primitive  man  must  have  made  certain 
elementary  observations  that  underlie  such  sciences 
as  psychology,  mathematics,  and  political  economy. 
The  elementary  emotions  associated  with  hunger  and 
with  satiety,  with  love  and  with  hatred,  must  have 
forced  themselves  upon  the  earliest  intelligence  that 
reached  the  plane  of  conscious  self -observation.  The 
capacity  to  count,  at  least  to  the  number  four  or 
five,  is  within  the  range  of  even  animal  intelligence. 
Certain  savages  have  gone  scarcely  farther  than  this; 
but  our  primeval  ancestor,  who  was  forging  on  towards 
civilization,  had  learned  to  count  his  fingers  and  toes, 
and  to  number  objects  about  him  by  fives  and  tens  in 
consequence,  before  he  passed  beyond  the  plane  of 
numerous  existing  barbarians.  How  much  beyond  this 
he  had  gone  we  need  not  attempt  to  inquire ;  but  the 
relatively  high  development  of  mathematics  in  the 
early  historical  period  suggests  that  primeval  man  had 
attained  a  not  inconsiderable  knowledge  of  numbers. 
The  humdrum  vocation  of  looking  after  a  numerous 
progeny  must  have  taught  the  mother  the  rudiments 
of  addition  and  subtraction ;  and  the  elements  of  mul- 
tiplication and  division  are  implied  in  the  capacity  to 

19 


A   HISTORY   OF   SCIENCE 

carry  on  even  the  rudest  form  of  barter,  such  as  the 
various  tribes  must  have  practised  from  an  early- 
day. 

As  to  political  ideas,  even  the  crudest  tribal  life  was 
based  on  certain  conceptions  of  ownership,  at  least  of 
tribal  ownership,  and  the  application  of  the  principle 
of  likeness  and  difference  to  which  we  have  already  re- 
ferred. Each  tribe,  of  course,  differed  in  some  regard 
from  other  tribes,  and  the  recognition  of  these  differ- 
ences implied  in  itself  a  political  classification.  A 
certain  tribe  took  possession  of  a  particular  hunting- 
ground,  which  became,  for  the  time  being,  its  home, 
and  over  which  it  came  to  exercise  certain  rights.  An 
invasion  of  this  territory  by  another  tribe  might  lead 
to  war,  and  the  banding  together  of  the  members  of 
the  tribe  to  repel  the  invader  implied  both  a  recogni- 
tion of  communal  unity  and  a  species  of  prejudice  in 
favor  of  that  community  that  constituted  a  primitive 
patriotism.  But  this  unity  of  action  in  opposing  an- 
other tribe  would  not  prevent  a  certain  rivalry  of  in- 
terest between  the  members  of  the  same  tribe,  which 
would  show  itself  more  and  more  prominently  as  the 
tribe  increased  in  size.  The  association  of  two  or 
more  persons  implies,  always,  the  ascendency  of  some 
and  the  subordination  of  others.  Leadership  and  sub- 
ordination are  necessary  correlatives  of  difference  of 
physical  and  mental  endowment,  and  rivalry  between 
leaders  would  inevitably  lead  to  the  formation  of  prim- 
itive political  parties.  With  the  ultimate  success  and 
ascendency  of  one  leader,  who  secures  either  absolute 
power  or  power  modified  in  accordance  with  the  ad- 
vice of  subordinate  leaders,  we  have  the  germs  of  an 

20 


PREHISTORIC   SCIENCE 

elaborate    political    system  —  an    embryo    science    of 
government. 

Meanwhile,  the  very  existence  of  such  a  community 
implies  the  recognition  on  the  part  of  its  members  of 
certain  individual  rights,  the  recognition  of  which  is 
essential  to  communal  harmony.  The  right  of  indi- 
vidual ownership  of  the  various  articles  and  imple- 
ments of  every-day  life  must  be  recognized,  or  all  har- 
mony would  be  at  an  end.  Certain  rules  of  justice — 
primitive  laws — must,  by  common  consent,  give  pro- 
tection to  the  weakest  members  of  the  community. 
Here  are  the  rudiments  of  a  system  of  ethics.  It  may 
seem  anomalous  to  speak  of  this  primitive  morality, 
this  early  recognition  of  the  principles  of  right  and 
wrong,  as  having  any  relation  to  science.  Yet,  rightly 
considered,  there  is  no  incongruity  in  such  a  citation. 
There  cannot  well  be  a  doubt  that  the  adoption  of 
those  broad  principles  of  right  and  wrong  which  under- 
lie the  entire  structure  of  modern  civilization  was  due 
to  scientific  induction, — in  other  words,  to  the  belief, 
based  on  observation  and  experience,  that  the  prin- 
ciples implied  were  essential  to  communal  progress. 
He  who  has  scanned  the  pageant  of  history  knows  how 
often  these  principles  seem  to  be  absent  in  the  inter- 
course of  men  and  nations.  Yet  the  ideal  is  always 
there  as  a  standard  by  which  all  deeds  are  judged. 

It  would  appear,  then,  that  the  entire  superstruct- 
ure of  later  science  had  its  foundation  in  the  knowledge 
and  practice  of  prehistoric  man.  The  civilization  of 
the  historical  period  could  not  have  advanced  as  it  has 
had  there  not  been  countless  generations  of  culture 

21 


A   HISTORY   OF   SCIENCE 

back  of  it.  The  new  principles  of  science  could  not 
have  been  evolved  had  there  not  been  great  basal 
principles  which  ages  of  unconscious  experiment  had 
impressed  upon  the  mind  of  our  race.  Due  meed  of 
praise  must  be  given,  then,  to  our  primitive  ancestor 
for  his  scientific  accomplishments ;  but  justice  demands 
that  we  should  look  a  little  farther  and  consider  the 
reverse  side  of  the  picture.  We  have  had  to  do,  thus 
far,  chiefly  with  the  positive  side  of  accomplishment. 
We  have  pointed  out  what  our  primitive  ancestor 
knew,  intimating,  perhaps,  the  limitations  of  his  knowl- 
edge ;  but  we  have  had  little  to  say  of  one  all-important 
feature  of  his  scientific  theorizing.  The  feature  in 
question  is  based  on  the  highly  scientific  desire  and 
propensity  to  find  explanations  for  the  phenomena  of 
nature.  Without  such  desire  no  progress  could  be 
made.  It  is,  as  we  have  seen,  the  generalizing  from 
experience  that  constitutes  real  scientific  progress; 
and  yet,  just  as  most  other  good  things  can  be  over- 
done, this  scientific  propensity  may  be  carried  to  a  dis- 
astrous excess. 

Primeval  man  did  not  escape  this  danger.  He  ob- 
served, he  reasoned,  he  found  explanations ;  but  he  did 
not  always  discriminate  as  to  the  logicality  of  his  rea- 
sonings. He  failed  to  recognize  the  limitations  of  his 
knowledge.  The  observed  uniformity  in  the  sequence 
of  certain  events  impressed  on  his  mind  the  idea  of 
cause  and  effect.  Proximate  causes  known,  he  sought 
remoter  causes;  childlike,  his  inquiring  mind  was  al- 
ways asking,  Why?  and,  childlike,  he  demanded  an 
explicit  answer.  If  the  forces  of  nature  seemed  to  com- 
bat him,  if  wind  and  rain  opposed  his  progress  and 

22 


PREHISTORIC   SCIENCE 

thunder  and  lightning  seemed  to  menace  his  existence, 
he  was  led  irrevocably  to  think  of  those  human  foes 
who  warred  with  him,  and  to  see,  back  of  the  warfare 
of  the  elements,  an  inscrutable  malevolent  intelligence 
which  took  this  method  to  express  its  displeasure. 
But  every  other  line  of  scientific  observation  leads 
equally,  following  back  a  sequence  of  events,  to  seem- 
ingly causeless  beginnings.  Modern  science  can  ex- 
plain the  lightning,  as  it  can  explain  a  great  number  of 
the  mysteries  which  the  primeval  intelligence  could  not 
penetrate.  But  the  primordial  man  could  not  wait  for 
the  revelations  of  scientific  investigation :  he  must  vault 
at  once  to  a  final  solution  of  all  scientific  problems. 
He  found  his  solution  by  peopling  the  world  with  in- 
visible forces,  anthropomorphic  in  their  conception, 
like  himself  in  their  thought  and  action,  differing  only 
in  the  limitations  of  their  powers.  His  own  dream- 
existence  gave  him  seeming  proof  of  the  existence  of  an 
alter  ego,  a  spiritual  portion  of  himself  that  could  dis- 
sever itself  from  his  body  and  wander  at  will ;  his  scien- 
tific inductions  seemed  to  tell  him  of  a  world  of  invisi- 
ble beings,  capable  of  influencing  him  for  good  or  ill. 
From  the  scientific  exercise  of  his  faculties  he  evolved 
the  all-encompassing  generalizations  of  invisible  and 
all-powerful  causes  back  of  the  phenomena  of  nature. 
These  generalizations,  early  developed  and  seemingly 
supported  by  the  observations  of  countless  generations, 
came  to  be  among  the  most  firmly  established  scientific 
inductions  of  our  primeval  ancestor.  They  obtained 
a  hold  upon  the  mentality  of  our  race  that  led  subse- 
quent generations  to  think  of  them,  sometimes  to 
speak  of  them,  as  "innate"  ideas.     The  observations 

23 


A   HISTORY   OF   SCIENCE 

upon  which  they  were  based  are  now,  for  the  most 
part,  susceptible  of  other  interpretations;  but  the  old 
interpretations  have  precedent  and  prejudice  back  of 
them,  and  they  represent  ideas  that  are  more  difficult 
than  almost  any  others  to  eradicate.  Always,  and 
everywhere,  superstitions  based  upon  unwarranted 
early  scientific  deductions  have  been  the  most  im- 
placable foes  to  the  progress  of  science.  Men  have 
built  systems  of  philosophy  around  their  conception  of 
anthropomorphic  deities;  they  have  linked  to  these 
systems  of  philosophy  the  allied  conception  of  the 
immutability  of  man's  spirit,  and  they  have  asked  that 
scientific  progress  should  stop  short  at  the  brink  of 
these  systems  of  philosophy  and  accept  their  dictates 
as  final.  Yet  there  is  not  to-day  in  existence,  and 
there  never  has  been,  one  jot  of  scientific  evidence 
for  the  existence  of  these  intangible  anthropomorphic 
powers  back  of  nature  that  is  not  susceptible  of  scien- 
tific challenge  and  of  more  logical  interpretation.  In 
despite  of  which  the  superstitious  beliefs  are  still  as 
firmly  fixed  in  the  minds  of  a  large  majority  of  our  race 
as  they  were  in  the  mind  of  our  prehistoric  ancestor. 
The  fact  of  this  baleful  heritage  must  not  be  forgotten 
in  estimating  the  debt  of  gratitude  which  historic  man 
owes  to  his  barbaric  predecessor. 


II 

EGYPTIAN   SCIENCE 

IN  the  previous  chapter  we  have  purposely  re- 
frained from  referring  to  any  particular  tribe  or 
race  of  historical  man.  Now,  however,  we  are  at  the 
beginnings  of  national  existence,  and  we  have  to  con- 
sider the  accomplishments  of  an  individual  race;  or 
rather,  perhaps,  of  two  or  more  races  that  occupied 
successively  the  same  geographical  territory.  But 
even  now  our  studies  must  for  a  time  remain  very  gen- 
eral; we  shall  see  little  or  nothing  of  the  deeds  of  in- 
dividual scientists  in  the  course  of  our  study  of  Egyp- 
tian culture.  We  are  still,  it  must  be  understood,  at 
the  beginnings  of  history;  indeed, we  must  first  bridge 
over  the  gap  from  the  prehistoric  before  we  may  find 
ourselves  fairly  on  the  line  of  march  of  historical  science. 
At  the  very  outset  we  may  well  ask  what  constitutes 
the  distinction  between  prehistoric  and  historic  epochs 
— a  distinction  which  has  been  constantly  implied  in 
much  that  we  have  said.  The  reply  savors  somewhat 
of  vagueness.  It  is  a  distinction  having  to  do,  not  so 
much  with  facts  of  human  progress  as  with  our  inter- 
pretation of  these  facts.  When  we  speak  of  the  dawn 
of  history  we  must  not  be  understood  to  imply  that, 
at  the  period  in  question,  there  was  any  sudden  change 
in  the  intellectual  status  of  the  human  race  or  in  the 
status  of  any  individual  tribe  or  nation  of  men.     What 

25 


A   HISTORY   OF   SCIENCE 

we  mean  is  that  modern  knowledge  has  penetrated  the 
mists  of  the  past  for  the  period  we  term  historical  with 
something  more  of  clearness  and  precision  than  it  has 
been  able  to  bring  to  bear  upon  yet  earlier  periods. 
New  accessions  of  knowledge  may  thus  shift  from  time 
to  time  the  bounds  of  the  so-called  historical  period. 
The  clearest  illustration  of  this  is  furnished  by  our  in- 
terpretation of  Egyptian  history.  Until  recently  the 
biblical  records  of  the  Hebrew  captivity  or  service, 
together  with  the  similar  account  of  Josephus,  furnished 
about  all  that  was  known  of  Egyptian  history  even  of 
so  comparatively  recent  a  time  as  that  of  Ramses  II. 
(fifteenth  century  B.C.),  and  from  that  period  on  there 
was  almost  a  complete  gap  until  the  story  was  taken 
up  by  the  Greek  historians  Herodotus  and  Diodorus. 
It  is  true  that  the  king-lists  of  the  Alexandrian  his- 
torian, Manetho,  were  all  along  accessible  in  somewhat 
garbled  copies.  But  at  best  they  seemed  to  supply 
unintelligible  lists  of  names  and  dates  which  no  one 
was  disposed  to  take  seriously.  That  they  were, 
broadly  speaking,  true  historical  records,  and  most 
important  historical  records  at  that,  was  not  recognized 
by  modern  scholars  until  fresh  light  had  been  thrown 
on  the  subject  from  altogether  new  sources. 

These  new  sources  of  knowledge  of  ancient  history 
demand  a  moment's  consideration.  They  are  all-im- 
portant because  they  have  been  the  means  of  extending 
the  historical  period  of  Egyptian  history  (using  the  word 
history  in  the  way  just  explained)  by  three  or  four 
thousand  years.  As  just  suggested,  that  historical 
period  carried  the  scholarship  of  the  early  nineteenth 
century  scarcely  beyond  the  fifteenth  century  B.C., but 

26 


EGYPTIAN   SCIENCE 

to-day's  vision  extends  with  tolerable  clearness  to 
about  the  middle  of  the  fifth  millennium  b.c.  This 
change  has  been  brought  about  chiefly  through  study 
of  the  Egyptian  hieroglyphics.  These  hieroglyphics 
constitute,  as  we  now  know,  a  highly  developed  system 
of  writing ;  a  system  that  was  practised  for  some  thou- 
sands of  years,  but  which  fell  utterly  into  disuse  in 
the  later  Roman  period,  and  the  knowledge  of  which 
passed  absolutely  from  the  mind  of  man.  For  about 
two  thousand  years  no  one  was  able  to  read,  with  any 
degree  of  explicitness,  a  single  character  of  this  strange 
script,  and  the  idea  became  prevalent  that  it  did  not 
constitute  a  real  system  of  writing,  but  only  a  more  or 
less  barbaric  system  of  religious  symbolism.  The  fal- 
sity of  this  view  was  shown  early  in  the  nineteenth 
century  when  Dr.  Thomas  Young  was  led,  through 
study  of  the  famous  trilingual  inscription  of  the 
Rosetta  stone,  to  make  the  first  successful  attempt 
at  clearing  up  the  mysteries  of  the  hieroglyphics. 

This  is  not  the  place  to  tell  the  story  of  his  fascinat- 
ing discoveries  and  those  of  his  successors.  That  story 
belongs  to  nineteenth-century  science,  not  to  the  science 
of  the  Egyptians.  Suffice  it  here  that  Young  gained 
the  first  clew  to  a  few  of  the  phonetic  values  of  the 
Egyptian  symbols,  and  that  the  work  of  discovery 
was  carried  on  and  vastly  extended  by  the  Frenchman 
Champollion,  a  little  later,  with  the  result  that  the  firm 
foundations  of  the  modern  science  of  Egyptology  were 
laid.  Subsequently  such  students  as  Rosellini  the 
Italian,  Lepsius  the  German,  and  Wilkinson  the  Eng- 
lishman, entered  the  field,  which  in  due  course  was  cul- 
tivated by  De  Rouge  in  France  and  Birch  in  England, 

27 


A   HISTORY    OF   SCIENCE 

and  by  such  distinguished  latter-day  workers  as  Chabas, 
Mariette,  Maspero,  Amelineau,  and  De  Morgan  among 
the  Frenchmen;  Professor  Petrie  and  Dr.  Budge  in 
England ;  and  Brugsch  Pasha  and  Professor  Erman  in 
Germany,  not  to  mention  a  large  coterie  of  somewhat 
less  familiar  names.  These  men  working,  some  of 
them  in  the  field  of  practical  exploration,  some  as 
students  of  the  Egyptian  language  and  writing,  have 
restored  to  us  a  tolerably  precise  knowledge  of  the 
history  of  Egypt  from  the  time  of  the  first  histori- 
cal king,  Mena,  whose  date  is  placed  at  about  the 
middle  of  the  fifth  century  B.C.  We  know  not  merely 
the  names  of  most  of  the  subsequent  rulers,  but  some- 
thing of  the  deeds' of  many  of  them;  and,  what  is  vastly 
more  important,  we  know,  thanks  to  the  modern  inter- 
pretation of  the  old  literature,  many  things  concerning 
the  life  of  the  people,  and  in  particular  concerning  their 
highest  culture,  their  methods  of  thought,  and  their 
scientific  attainments,  which  might  well  have  been 
supposed  to  be  past  finding  out.  Nor  has  modern  in- 
vestigation halted  with  the  time  of  the  first  kings ;  the 
recent  explorations  of  such  archaeologists  as  Amelineau, 
De  Morgan,  and  Petrie  have  brought  to  light  numer- 
ous remains  of  what  is  now  spoken  of  as  the  predynastic 
period — a  period  when  the  inhabitants  of  the  Nile  Val- 
ley used  implements  of  chipped  stone,  when  their  pot- 
tery was  made  without  the  use  of  the  potter's  wheel, 
and  when  they  buried  their  dead  in  curiously  cramped 
attitudes  without  attempt  at  mummification.  These 
aboriginal  inhabitants  of  Egypt  cannot  perhaps  with 
strict  propriety  be  spoken  of  as  living  within  the  his- 
torical period,  since  we  cannot  date  their  relics  with 


EGYPTIAN   SCIENCE 

any  accuracy.  But  they  give  us  glimpses  of  the  early 
stages  of  civilization  upon  which  the  Egyptians  of  the 
dynastic  period  were  to  advance. 

It  is  held  that  the  nascent  civilization  of  these  Egyp- 
tians of  the  Neolithic,  or  late  Stone  Age,  was  over- 
thrown by  the  invading  hosts  of  a  more  highly  civilized 
race  which  probably  came  from  the  East,  and  which 
may  have  been  of  a  Semitic  stock.  The  presumption 
is  that  this  invading  people  brought  with  it  a  knowl- 
edge of  the  arts  of  war  and  peace,  developed  or  adopted 
in  its  old  home.  The  introduction  of  these  arts  served 
to  bridge  somewhat  suddenly,  so  far  as  Egypt  is  con- 
cerned, that  gap  between  the  prehistoric  and  the  his- 
toric stage  of  culture  to  which  we  have  all  along  re- 
ferred. The  essential  structure  of  that  bridge,  let  it 
now  be  clearly  understood,  consisted  of  a  single  ele- 
ment. That  element  is  the  capacity  to  make  written 
records:  a  knowledge  of  the  art  of  writing.  Clearly 
understood,  it  is  this  element  of  knowledge  that  forms 
the  line  bounding  the  historical  period.  Numberless 
mementos  are  in  existence  that  tell  of  the  intellectual 
activities  of  prehistoric  man;  such  mementos  as  flint 
implements,  pieces  of  pottery,  and  fragments  of  bone, 
inscribed  with  pictures  that  may  fairly  be  spoken 
of  as  works  of  art ;  but  so  long  as  no  written  word  ac- 
companies these  records,  so  long  as  no  name  of  king  or 
scribe  comes  down  to  us,  we  feel  that  these  records  be- 
long to  the  domain  of  archaeology  rather  than  to  that  of 
history.  Yet  it  must  be  understood  all  along  that  these 
two  domains  shade  one  into  the  other  and,  it  has  al- 
ready been  urged,  that  the  distinction  between  them 
is  one  that  pertains  rather  to  modern  scholarship  than 

29 


A   HISTORY   OF   SCIENCE 

to  the  development  of  civilization  itself.  Bearing  this 
distinction  still  in  mind,  and  recalling  that  the  histori- 
cal period,  which  is  to  be  the  field  of  our  observation 
throughout  the  rest  of  our  studies,  extends  for  Egypt 
well  back  into  the  fifth  millennium  B.C.,  let  us  briefly 
review  the  practical  phases  of  that  civilization  to 
which  the  Egyptian  had  attained  before  the  beginning 
of  the  dynastic  period.  Since  theoretical  science  is 
everywhere  linked  with  the  mechanical  arts,  this  sur- 
vey will  give  us  a  clear  comprehension  of  the  field  that 
lies  open  for  the  progress  of  science  in  the  long  stages 
of  historical  time  upon  which  we  are  just  entering. 

We  may  pass  over  such  rudimentary  advances  in  the 
direction  of  civilization  as  are  implied  in  the  use  of 
articulate  language,  the  application  of  fire  to  the  uses 
of  man,  and  the  systematic  making  of  dwellings  of  one 
sort  or  another,  since  all  of  these  are  stages  of  progress 
that  were  reached  very  early  in  the  prehistoric  period. 
What  more  directly  concerns  us  is  to  note  that  a  really 
high  stage  of  mechanical  development  had  been  reached 
before  the  dawnings  of  Egyptian  history  proper.  All 
manner  of  household  utensils  were  employed ;  the  pot- 
ter's wheel  aided  in  the  construction  of  a  great  variety 
of  earthen  vessels ;  weaving  had  become  a  fine  art,  and 
weapons  of  bronze,  including  axes,  spears,  knives,  and 
arrow-heads,  were  in  constant  use.  Animals  had  long 
been  domesticated,  in  particular  the  dog,  the  cat,  and 
the  ox ;  the  horse  was  introduced  later  from  the  East. 
The  practical  arts  of  agriculture  were  practised  almost 
as  they  are  at  the  present  day  in  Egypt,  there  being, 
of  course,  the  same  dependence  then  as  now  upon  the 
inundations  of  the  Nile. 

30 


EGYPTIAN   SCIENCE 

As  to  government,  the  Egyptian  of  the  first  dynasty 
regarded  his  king  as  a  demi-god  to  be  actually  deified 
after  his  death,  and  this  point  of  view  was  not  changed 
throughout  the  stages  of  later  Egyptian  history.  In 
point  of  art,  marvellous  advances  upon  the  skill  of 
the  prehistoric  man  had  been  made,  probably  in  part 
under  Asiatic  influences,  and  that  unique  style  of  stilt- 
ed yet  expressive  drawing  had  come  into  vogue,  which 
was  to  be  remembered  in  after  times  as  typically  Egyp- 
tian. More  important  than  all  else,  our  Egyptian  of 
the  earliest  historical  period  was  in  possession  of  the 
art  of  writing.  He  had  begun  to  make  those  specific 
records  which  were  impossible  to  the  man  of  the  Stone 
Age,  and  thus  he  had  entered  fully  upon  the  way  of 
historical  progress  which,  as  already  pointed  out,  has 
its  very  foundation  in  written  records.  From  now  on 
the  deeds  of  individual  kings  could  find  specific  record. 
It  began  to  be  possible  to  fix  the  chronology  of  re- 
mote events  with  some  accuracy;  and  with  this  same 
fixing  of  chronologies  came  the  advent  of  true  his- 
tory. The  period  which  precedes  what  is  usually 
spoken  of  as  the  first  dynasty  in  Egypt  is  one  into 
which  the  present-day  searcher  is  still  able  to  see  but 
darkly.  The  evidence  seems  to  suggest  than  an  in- 
vasion of  relatively  cultured  people  from  the  East  over- 
threw, and  in  time  supplanted,  the  Neolithic  civiliza- 
tion of  the  Nile  Valley.  It  is  impossible  to  date  this  in- 
vasion accurately,  but  it  cannot  well  have  been  later  than 
the  year  5000  B.C.,  and  it  may  have  been  a  great  many 
centuries  earlier  than  this.  Be  the  exact  dates  what 
they  may,  we  find  the  Egyptian  of  the  fifth  millennium 
B.C.  in  full  possession  of  a  highly  organized  civilization. 

31 


A   HISTORY    OF   SCIENCE 

All  subsequent  ages  have  marvelled  at  the  pyramids, 
some  of  which  date  from  about  the  year  4000  B.C., 
though  we  may  note  in  passing  that  these  dates  must 
not  be  taken  too  literally.  The  chronology  of  ancient 
Egypt  cannot  as  yet  be  fixed  with  exact  accuracy,  but 
the  disagreements  between  the  various  students  of  the 
subject  need  give  us  little  concern.  For  our  present 
purpose  it  does  not  in  the  least  matter  whether  the 
pyramids  were  built  three  thousand  or  four  thousand 
years  before  the  beginning  of  our  era.  It  suffices  that 
they  date  back  to  a  period  long  antecedent  to  the 
beginnings  of  civilization  in  Western  Europe.  They 
prove  that  the  Egyptian  of  that  early  day  had  attained 
a  knowledge  of  practical  mechanics  which,  even  from 
the  twentieth  -  century  point  of  view,  is  not  to  be 
spoken  of  lightly.  It  has  sometimes  been  suggested 
that  these  mighty  pyramids,  built  as  they  are  of  great 
blocks  of  stone,  speak  for  an  almost  miraculous  knowl- 
edge on  the  part  of  their  builders ;  but  a  saner  view  of 
the  conditions  gives  no  warrant  for  this  thought.  Dio- 
dorus,  the  Sicilian,  in  his  famous  World's  History, 
written  about  the  beginning  of  our  era,  explains  the 
building  of  the  pyramids  by  suggesting  that  great 
quantities  of  earth  were  piled  against  the  side  of  the 
rising  structure  to  form  an  inclined  plane  up  which 
the  blocks  of  stone  were  dragged.  He  gives  us  cer- 
tain figures,  based,  doubtless,  on  reports  'made  to 
him  by  Egyptian  priests,  who  in  turn  drew  upon  the 
traditions  of  their  country,  perhaps  even  upon  written 
records  no  longer  preserved.  He  says  that  one  hun- 
dred and  twenty  thousand  men  were  employed  in  the 
construction  of  the  largest  pyramid,  and  that,  not- 

32 


EGYPTIAN   SCIENCE 

withstanding  the  size  of  this  host  of  workers,  the  task 
occupied  twenty  years.  We  must  not  place  too  much 
dependence  upon  such  figures  as  these,  for  the  ancient 
historians  are  notoriously  given  to  exaggeration  in 
recording  numbers ;  yet  we  need  not  doubt  that  the  re- 
port given  by  Diodorus  is  substantially  accurate  in  its 
main  outlines  as  to  the  method  through  which  the 
pyramids  were  constructed.  A  host  of  men  putting 
their  added  weight  and  strength  to  the  task,  with  the 
aid  of  ropes,  pulleys,  rollers,  and  levers,  and  utilizing 
the  principle  of  the  inclined  plane,  could  undoubtedly 
move  and  elevate  and  place  in  position  the  largest 
blocks  that  enter  into  the  pyramids  or — what  seems 
even  more  wonderful  —  the  most  gigantic  obelisks, 
without  the  aid  of  any  other  kind  of  mechanism  or  of 
any  more  occult  power.  The  same  hands  could,  as 
Diodorus  suggests,  remove  all  trace  of  the  debris  of 
construction  and  leave  the  pyramids  and  obelisks 
standing  in  weird  isolation,  as  if  sprung  into  being 
through  a  miracle. 

ASTRONOMICAL   SCIENCE 

It  has  been  necessary  to  bear  in  mind  these  phases 
of  practical  civilization  because  much  that  we  know 
of  the  purely  scientific  attainments  of  the  Egyptians 
is  based  upon  modern  observation  of  their  pyramids 
and  temples.  It  was  early  observed,  for  example, 
that  the  pyramids  are  obviously  oriented  as  regards 
the  direction  in  which  they  face,  in  strict  accordance 
with  some  astronomical  principle.  Early  in  the  nine- 
teenth century  the  Frenchman  Biot  made  interesting 
studies  in  regard  to  this  subject,  and  a  hundred  years 

VOL.  I.— 3  33 


A    HISTORY    OF   SCIENCE 

later,  in  our  own  time,  Sir  Joseph  Norman  Lockyer,  fol- 
lowing up  the  work  of  various  intermediary  observers, 
has  given  the  subject  much  attention,  making  it  the 
central  theme  of  his  work  on  The  Dawn  of  Astronomy.1 
Lockyer' s  researches  make  it  clear  that  in  the  main  the 
temples  of  Egypt  were  oriented  with  reference  to  the 
point  at  which  the  sun  rises  on  the  day  of  the  summer 
solstice.  The  time  of  the  solstice  had  peculiar  in- 
terest for  the  Egyptians,  because  it  corresponded 
rather  closely  with  the  time  of  the  rising  of  the  Nile. 
The  floods  of  that  river  appear  with  very  great  regu- 
larity; the  on-rushing  tide  reaches  the  region  of  Heli- 
opolis  and  Memphis  almost  precisely  on  the  day  of  the 
summer  solstice.  The  time  varies  at  different  stages 
of  the  river's  course,  but  as  the  civilization  of  the  early 
dynasties  centred  at  Memphis,  observations  made  at 
this  place  had  widest  vogue. 

Considering  the  all-essential  character  of  the  Nile 
floods — without  which  civilization  would  be  impossi- 
ble in  Egypt — it  is  not  strange  that  the  time  of  their 
appearance  should  be  taken  as  marking  the  beginning 
of  a  new  year.  The  fact  that  their  coming  coincides 
with  the  solstice  makes  such  a  division  of  the  calendar 
perfectly  natural.  In  point  of  fact,  from  the  earliest 
periods  of  which  records  have  come  down  to  us,  the 
new  year  of  the  Egyptians  dates  from  the  summer 
solstice.  It  is  certain  that  from  the  earliest  historical 
periods  the  Egyptians  were  aware  of  the  approximate 
length  of  the  year.  It  would  be  strange  were  it  other- 
wise, considering  the  ease  with  which  a  record  of  days 
could  be  kept  from  Nile  flood  to  Nile  flood,  or  from 
solstice  to  solstice.     But  this,  of  course,  applies  only 

34 


EGYPTIAN   SCIENCE 

to  an  approximate  count.  There  is  some  reason  to 
believe  that  in  the  earliest  period  the  Egyptians  made 
this  count  only  360  days.  The  fact  that  their  year 
was  divided  into  twelve  months  of  thirty  days  each 
lends  color  to  this  belief;  but,  in  any  event,  the  mis- 
take was  discovered  in  due  time  and  a  partial  remedy 
was  applied  through  the  interpolation  of  a  "little 
month"  of  five  days  between  the  end  of  the  twelfth 
month  and  the  new  year.  This  nearly  but  not  quite 
remedied  the  matter.  What  it  obviously  failed  to  do 
was  to  take  account  of  that  additional  quarter  of  a  day 
which  really  rounds  out  the  actual  year. 

It  would  have  been  a  vastly  convenient  thing  for  hu- 
manity had  it  chanced  that  the  earth  had  so  accommo- 
dated its  rotary  motion  with  its  speed  of  transit  about 
the  sun  as  to  make  its  annual  flight  in  precisely  360  days. 
Twelve  lunar  months  of  thirty  days  each  would  then 
have  coincided  exactly  with  the  solar  year,  and  most 
of  the  complexities  of  the  calendar,  which  have  so  puz- 
zled historical  students,  would  have  been  avoided ;  but, 
on  the  other  hand,  perhaps  this  very  simplicity  would 
have  proved  detrimental  to  astronomical  science  by 
preventing  men  from  searching  the  heavens  as  care- 
fully as  they  have  done.  Be  that  as  it  may,  the  com- 
plexity exists.  The  actual  year  of  three  hundred  and 
sixty -five  and  (about)  one -quarter  days  cannot  be 
divided  evenly  into  months,  and  some  such  expedient 
as  the  intercalation  of  days  here  and  there  is  essential, 
else  the  calendar  will  become  absolutely  out  of  har- 
mony with  the  seasons. 

In  the  case  of  the  Egyptians,  the  attempt  at  adjust- 
ment was  made,  as  just  noted,  by  the  introduction  of 

35 


A   HISTORY   OF   SCIENCE 

the  five  days,  constituting  what  the  Egyptians  them- 
selves termed  "the  five  days  over  and  above  the 
year."  These  so-called  epagomenal  days  were  un- 
doubtedly introduced  at  a  very  early  period.  Mas- 
pero  holds  that  they  were  in  use  before  the  first  Thinite 
dynasty,  citing  in  evidence  the  fact  that  the  legend  of 
Osiris  explains  these  days  as  having  been  created  by 
the  god  Thot  in  order  to  permit  Nuit  to  give  birth  to 
all  her  children ;  this  expedient  being  necessary  to  over- 
come a  ban  which  had  been  pronounced  against  Nuit, 
according  to  which  she  could  not  give  birth  to  children 
on  any  day  of  the  year.  But,  of  course,  the  five  addi- 
tional days  do  not  suffice  fully  to  rectify  the  calendar. 
There  remains  the  additional  quarter  of  a  day  to  be 
accounted  for.  This,  of  course,  amounts  to  a  full  day 
every  fourth  year.  We  shall  see  that  later  Alexan- 
drian science  hit  upon  the  expedient  of  adding  a  day 
to  every  fourth  year;  an  expedient  which  the  Julian 
calendar  adopted  and  which  still  gives  us  our  familiar 
leap-year.  But,  unfortunately,  the  ancient  Egyptian 
failed  to  recognize  the  need  of  this  additional  day,  or 
if  he  did  recognize  it  he  failed  to  act  on  his  knowledge, 
and  so  it  happened  that,  starting  somewhere  back  in 
the  remote  past  with  a  new  year's  day  that  coincided 
with  the  inundation  of  the  Nile,  there  was  a  constantly 
shifting  maladjustment  of  calendar  and  seasons  as  time 
went  on. 

The  Egyptian  seasons,  it  should  be  explained,  were 
three  in  number:  the  season  of  the  inundation,  the  sea- 
son of  the  seed-time,  and  the  season  of  the  harvest; 
each  season  being,  of  course,  four  months  in  extent. 
Originally,  as  just  mentioned,  the  season  of  the  inun- 

36 


c>  o 
~3 


S" 

W 
W 

t) 

2 

O 

X 

o  x 

o 

n>    r" 

^  - 

K 

3  * 

o  o 

EGYPTIAN   SCIENCE 

dations  began  and  coincided  with  the  actual  time  of 
inundation.  The  more  precise  fixing  of  new  year's 
day  was  accomplished  through  observation  of  the  time 
of  the  so-called  heliacal  rising  of  the  dog-star,  Sirius, 
which  bore  the  Egyptian  name  Sothis.  It  chances 
that,  as  viewed  from  about  the  region  of  Heliopolis, 
the  sun  at  the  time  of  the  summer  solstice  occupies  an 
apparent  position  in  the  heavens  close  to  the  dog-star. 
Now,  as  is  well  known,!-  the  Egyptians,  seeing  divinity 
back  of  almost  every  phenomenon  of  naturejvery  nat- 
urallyjjpaid  particular  reverence  to  so  obviously  in- 
fluential a  personage  as  the  sun  -  god.  |  In  particular 
they  thought  it  fitting  to  do  homage  to  him  just  as  he 
was  starting  out  on  his  tour  of  Egypt  in  the  morning; 
and  that  they  might  know  the  precise  moment  of  his 
coming,  the  Egyptian  astronomer  priests,  perched  on 
the  hill-tops  near  their  temples,  were  wont  to  scan  the 
eastern  horizon  with  reference  to  some  star  which  had 
been  observed  to  precede  the  solar  luminary.  Of 
course  the  precession  of  the  equinoxes,  due  to  that 
axial  wobble  in  which  our  clumsy  earth  indulges,  would 
change  the  apparent  position  of  the  fixed  stars  in  ref- 
erence to  the  sun,  so  that  the  same  star  could  not  do 
service  as  heliacal  messenger  indefinitely;  but,  on  the 
other  hand,  these  changes  are  so  slow  that  observa- 
tions by  many  generations  of  astronomers  would  be 
required  to  detect  the  shifting.  It  is  believed  by 
Lockyer,  though  the  evidence  is  not  quite  demonstra- 
tive, that  the  astronomical  observations  of  the  Egyp- 
tians date  back  to  a  period  when  Sothis,  the  dog-star, 
was  not  in  close  association  with  the  sun  on  the  morn- 
ing of  the  summer  solstice.     Yet,  according  to  the  cal- 

37 


A   HISTORY   OF   SCIENCE 

dilations  of  Biot,  the  heliacal  rising  of  Sothis  at  the 
solstice  was  noted  as  early  as  the  year  3285  B.C.,  and 
it  is  certain  that  this  star  continued  throughout  sub- 
sequent centuries  to  keep  this  position  of  peculiar 
prestige.  Hence  it  was  that  Sothis  came  to  be  asso- 
ciated with  I  sis,  one  of  the  most  important  divinities 
of  Egypt,  and  that  the  day  in  which  Sothis  was  first 
visible  in  the  morning  sky  marked  the  beginning  of  the 
new  year;  that  day  coinciding,  as  already  noted,  with 
the  summer  solstice  and  with  the  beginning  of  the  Nile 
flow. 

But  now  for  the  difficulties  introduced  by  that  un- 
reckoned  quarter  of  a  day.  Obviously  with  a  calendar 
of  365  days  only,  at  the  end  of  four  years,  the  calendar 
year,  or  vague  year,  as  the  Egyptians  came  to  call  it, 
had  gained  by  one  full  day  upon  the  actual  solar  year — 
that  is  to  say,  the  heliacal  rising  of  Sothis,  the  dog- 
star,  would  not  occur  on  new  year's  day  of  the  faulty 
calendar,  but  a  day  later.  And  with  each  succeeding 
period  of  four  years  the  day  of  heliacal  rising,  which 
marked  the  true  beginning  of  the  year — and  which  still, 
of  course,  coincided  with  the  inundation — would  have 
fallen  another  day  behind  the  calendar.  In  the  course 
of  120  years  an  entire  month  would  be  lost;  and  in  480 
years  so  great  would  become  the  shifting  that  the  sea- 
sons would  be  altogether  misplaced;  the  actual  time 
of  inundations  corresponding  with  what  the  calendar 
registered  as  the  seed-time,  and  the  actual  seed-.time 
in  turn  corresponding  with  the  harvest-time  of  the 
calendar. 

At  first  thought  this  seems  very  awkward  and  con- 
fusing, but  in  all  probability  the  effects  were  by  no 

38 


EGYPTIAN   SCIENCE 

means  so  much  so  in  actual  practice.  We  need  go  no 
farther  than  to  our  own  experience  to  know  that  the 
names  of  seasons,  as  of  months  and  days,  come  to  have 
in  the  minds  of  most  of  us  a  purely  conventional  sig- 
nificance. Few  of  us  stop  to  give  a  thought  to  the 
meaning  of  the  words  January,  February,  etc.,  except 
as  they  connote  certain  climatic  conditions.  If,  then, 
our  own  calendar  were  so  defective  that  in  the  course 
of  1 20  years  the  month  of  February  had  shifted  back 
to  occupy  the  position  of  the  original  January,  the 
change  would  have  been  so  gradual,  covering  the 
period  of  two  life-times  or  of  four  or  five  average  gen- 
erations, that  it  might  well  escape  general  observation. 
Each  succeeding  generation  of  Egyptians,  then,  may 
not  improbably  have  associated  the  names  of  the  sea- 
sons with  the  contemporary  climatic  conditions, 
troubling  themselves  little  with  the  thought  that  in  an 
earlier  age  the  climatic  conditions  for  each  period  of 
the  calendar  were  quite  different.  We  cannot  well 
suppose,  however,  that  the  astronomer  priests  were 
oblivious  to  the  true  state  of  things.  Upon  them  de- 
volved the  duty  of  predicting  the  time  of  the  Nile 
flood;  a  duty  they  were  enabled  to  perform  without 
difficulty  through  observation  of  the  rising  of  the  sol- 
stitial sun  and  its  Sothic  messenger.  To  these  ob- 
servers'it  must  finally  have  been  apparent  that  the 
shifting  of  the  seasons  was  at  the  rate  of  one  day  in 
four  years;  this  known,  it  required  no  great  mathe- 
matical skill  to  compute  that  this  shifting  would  finally 
effect  a  complete  circuit  of  the  calendar,  so  that  after 
(4  x  365  =)  1460  years  the  first  day  of  the  calendar  year 
would  again  coincide  with  the  heliacal  rising  of  Sothis 

39 


A   HISTORY   OF   SCIENCE 

and  with  the  coming  of  the  Nile  flood.  In  other  words, 
1 46 1  vague  years  or  Egyptian  calendar  years  of  365 
days  each  correspond  to  1460  actual  solar  years  of 
365 1  days  each.  This  period,  measured  thus  by  the 
heliacal  rising  of  Sothis,  is  spoken  of  as  the  Sothic 
cycle. 

To  us  who  are  trained  from  childhood  to  understand 
that  the  year  consists  of  (approximately)  36  5-4-  days,  and 
to  know  that  the  calendar  may  be  regulated  approxi- 
mately by  the  introduction  of  an  extra  day  every  fourth 
year,  this  recognition  of  the  Sothic  cycle  seems  simple 
enough.  Yet  if  the  average  man  of  us  will  reflect  how 
little  he  knows,  of  his  own  knowledge,  of  the  exact 
length  of  the  year,  it  will  soon  become  evident  that  the 
appreciation  of  the  faults  of  the  calendar  and  the 
knowledge  of  its  periodical  adjustment  constituted  a 
relatively  high  development  of  scientific  knowledge 
on  the  part  of  the  Egyptian  astronomer.  It  may  be 
added  that  various  efforts  to  reform  the  calendar  were 
made  by  the  ancient  Egyptians,  but  that  they  cannot 
be  credited  with  a  satisfactory  solution  of  the  problem ; 
for,  of  course,  the  Alexandrian  scientists  of  the  Ptole- 
maic period  (whose  work  we  shall  have  occasion  to  re- 
view presently)  were  not  Egyptians  in  any  proper 
sense  of  the  word,  but  Greeks. 

Since  so  much  of  the  time  of  the  astronomer  priests 
was  devoted  to  observation  of  the  heavenly  bodies,  it  is 
not  surprising  that  they  should  have  mapped  out  the 
apparent  course  of  the  moon  and  the  visible  planets  in 
their  nightly  tour  of  the  heavens,  and  that  they  should 
have  divided  the  stars  of  the  firmament  into  more  or 
less  arbitrary  groups  or  constellations.     That  they  did 

40 


TWELVE    STAGES    IN    THE    LIFE    OF    THE    SUN    AND    ITS    TWELVE 
FORMS    THROUGHOUT    THE    DAY 

(From  a  drawing  by  Faucher-Gudin   in   Maspero's  Dawn  of  Civilization,  from 
the  ceiling  of  the  Hall  of  the   New  Year  at  Edfu.) 


EGYPTIAN    SCIENCE 

so  is.  evidenced  by  various  sculptured  representations 
of  constellations  corresponding  to  signs  of  the  zodiac 
which  still  ornament  the  ceilings  of  various  ancient 
temples.  Unfortunately  the  decorative  sense,  which 
was  always  predominant  with  the  Egyptian  sculptor, 
led  him  to  take  various  liberties  with  the  distribution 
of  figures  in  these  representations  of  the  constellations, 
so  that  the  inferences  drawn  from  them  as  to  the  exact 
map  of  the  heavens  as  the  Egyptians  conceived  it  can- 
not be  fully  relied  upon.  It  appears,  however,  that 
the  Egyptian  astronomer  divided  the  zodiac  into  twen- 
ty-four decani,  or  constellations.  The  arbitrary  group- 
ings of  figures,  with  the  aid  of  which  these  are  de- 
lineated, bear  a  close  resemblance  to  the  equally  ar- 
bitrary outlines  which  we  are  still  accustomed  to  use 
for  the  same  purpose. 

IDEAS    OF   COSMOLOGY 

In  viewing  this  astronomical  system  of  the  Egyp- 
tians one  cannot  avoid  the  question  as  to  just  what 
interpretation  was  placed  upon  it  as  regards  the  actual 
mechanical  structure  of  the  universe.  A  proximal 
answer  to  the  question  is  supplied  us  with  a  good  deal 
of  clearness.  It  appears  that  the  Egyptian  conceived 
the  sky  as  a  sort  of  tangible  or  material  roof  placed 
above  the  world,  and  supported  at  each  of  its  four  cor- 
ners by  a  column  or  pillar,  which  was  later  on  conceived 
as  a  great  mountain.  The  earth  itself  was  conceived 
to  be  a  rectangular  box,  longer  from  north  to  south 
than  from  east  to  west ;  the  upper  surface  of  this  box, 
upon  which  man  lived,  being  slightly  concave  and  hav- 
ing, of  course,  the  valley  of  the  Nile  as  its  centre.     The 

4i 


A   HISTORY   OF   SCIENCE 

pillars  of  support  were  situated  at  the  points  of  the 
compass;  the  northern  one  being  located  beyond  the 
Mediterranean  Sea;  the  southern  one  away  beyond 
the  habitable  regions  towards  the  source  of  the  Nile, 
and  the  eastern  and  western  ones  in  equally  inaccessi- 
ble regions.  Circling  about  the  southern  side  of  the 
world  was  a  great  river  suspended  in  mid-air  on  some- 
thing comparable  to  mountain  cliffs ;  on  which  river  the 
sun-god  made  his  daily  course  in  a  boat,  fighting  day 
by  day  his  ever-recurring  battle  against  Set,  the  demon 
of  darkness.  The  wide  channel  of  this  river  enabled 
the  sun-god  to  alter  his  course  from  time  to  time,  as  he 
is  observed  to  do ;  in  winter  directing  his  bark  towards 
the  farther  bank  of  the  channel;  in  summer  gliding 
close  to  the  nearer  bank.  As  to  the  stars,  they  were 
similar  lights,  suspended  from  the  vault  of  the  heaven ; 
but  just  how  their  observed  motion  of  translation 
across  the  heavens  was  explained  is  not  apparent. 
It  is  more  than  probable  that  no  one  explanation  was 
universally  accepted. 

In  explaining  the  origin  of  this  mechanism  of  the 
heavens,  the  Egyptian  imagination  ran  riot.  Each 
separate  part  of  Egypt  had  its  own  hierarchy  of  gods, 
and  more  or  less  its  own  explanations  of  cosmogony. 
There  does  not  appear  to  have  been  any  one  central 
story  of  creation  that  found  universal  acceptance,  any 
more  than  there  was  one  specific  deity  everywhere 
recognized  as  supreme  among  the  gods.  Perhaps  the 
most  interesting  of  the  cosmogonic  myths  was  that 
which  conceived  that  Nuit,  the  goddess  of  night,  had 
been  torn  from  the  arms  of  her  husband,  Sibu  the  earth- 
god,  and  elevated  to  the  sky  despite  her  protests  and 

42 


SB 

~ 

■d 

a 

a> 

W 

0!      g 

> 

EGYPTIAN   SCIENCE 

her  husband's  struggles,  there  to  remain  supported  by 
her  four  limbs,  which  became  metamorphosed  into  the 
pillars,  or  mountains,  already  mentioned.  The  forci- 
ble elevation  of  Nuit  had  been  effected  on  the  day  of 
creation  by  a  new  god,  Shu,  who  came  forth  from  the 
primeval  waters.  A  painting  on  the  mummy  case  of 
one  Betuhamon,  now  in  the  Turin  Museum,  illustrates, 
in  the  graphic  manner  so  characteristic  of  the  Egyp- 
tians, this  act  of  creation.  As  Maspero2  points  out,  the 
struggle  of  Sibu  resulted  in  contorted  attitudes  to 
which  the  irregularities  of  the  earth's  surface  are  to  be 
ascribed. 

In  contemplating  such  a  scheme  of  celestial  mechan- 
ics as  that  just  outlined,  one  cannot  avoid  raising  the 
question  as  to  just  the  degree  of  literalness  which  the 
Egyptians  themselves  put  upon  it.  We  know  how 
essentially  eye-minded  the  Egyptian  was,  to  use  a 
modern  psychological  phrase — that  is  to  say,  how  essen- 
tial to  him  it  seemed  that  all  his  conceptions  should  be 
visualized.  The  evidences  of  this  are  everywhere:  all 
his  gods  were  made  tangible;  he  believed  in  the  im- 
mortality of  the  soul,  yet  he  could  not  conceive  of  such 
immortality  except  in  association  with  an  immortal 
body;  he  must  mummify  the  body  of  the  dead,  else, 
as  he  firmly  believed,  the  dissolution  of  the  spirit 
would  take  place  along  with  the  dissolution  of  the  body 
itself.  His  world  was  peopled  everywhere  with  spirits, 
but  they  were  spirits  associated  always  with  corporeal 
bodies;  his  gods  found  lodgment  in  sun  and  moon  and 
stars;  in  earth  and  water;  in  the  bodies  of  reptiles 
and  birds  and  mammals.  He  worshipped  all  of  these 
things:  the  sun,  the  moon,  water,  earth,  the  spirit  of 

43 


A   HISTORY   OF   SCIENCE 

the  Nile,  the  ibis,  the  cat,  the  ram,  and  apis  the  bull; 
but,  so  far  as  we  can  judge,  his  imagination  did  not 
reach  to  the  idea  of  an  absolutely  incorporeal  deity. 
Similarly  his  conception  of  the  mechanism  of  the 
heavens  must  be  a  tangibly  mechanical  one.  He  must 
think  of  the  starry  firmament  as  a  substantial  entity 
which  could  not  defy  the  law  of  gravitation,  and  which, 
therefore,  must  have  the  same  manner  of  support  as  is 
required  by  the  roof  of  a  house  or  temple.  We  know 
that  this  idea  of  the  materiality  of  the  firmament 
found  elaborate  expression  in  those  later  cosmological 
guesses  which  were  to  dominate  the  thought  of  Eu- 
rope until  the  time  of  Newton.  We  need  not  doubt, 
therefore,  that  for  the  Egyptian  this  solid  vault  of  the 
heavens  had  a  very  real  existence.  If  now  and  then 
some  dreamer  conceived  the  great  bodies  of  the  firma- 
ment as  floating  in  a  less  material  plenum — and  such 
iconoclastic  dreamers  there  are  in  all  ages — no  record 
of  his  musings  has  come  down  to  us,  and  we  must  freely 
admit  that  if  such  thoughts  existed  they  were  alien  to 
the  character  of  the  Egyptian  mind  as  a  whole. 

While  the  Egyptians  conceived  the  heavenly  bodies 
as  the  abiding-place  of  various  of  their  deities,  it  does 
not  appear  that  they  practised  astrology  in  the  later 
acceptance  of  that  word.  This  is  the  more  remarkable 
since  the  conception  of  lucky  and  unlucky  days  was 
carried  by  the  Egyptians  to  the  extremes  of  absurdity. 
"One  day  was  lucky  or  unlucky,"  says  Erman,3  "ac- 
cording as  a  good  or  bad  mythological  incident  took 
place  on  that  day.  For  instance,  the  ist  of  Mechir,  on 
which  day  the  sky  was  raised,  and  the  27th  of  Athyr, 
when  Horus  and  Set  concluded  peace  together  and 

44 


EGYPTIAN    SCIENCE 

divided  the  world  between  them,  were  lucky  days ;  on 
the  other  hand,  the  14th  of  Tybi,  on  which  Isis  and 
Nephthys  mourned  for  Osiris,  was  an  unlucky  day. 
With  the  unlucky  days,  which,  fortunately,  were  less  in 
number  than  the  lucky  days,  they  distinguished  dif- 
ferent degrees  of  ill-luck.  Some  were  very  unlucky, 
others  only  threatened  ill-luck,  and  many,  like  the  17th 
and  the  27th  Choiakh,  were  partly  good  and  partly 
bad  according  to  the  time  of  day.  Lucky  days  might, 
as  a  rule,  be  disregarded.  At  most  it  might  be  as  well 
to  visit  some  specially  renowned  temple,  or  to  'cele- 
brate a  joyful  day  at  home,'  but  no  particular  precau- 
tions were  really  necessary;  and,  above  all,  it  was  said, 
'what  thou  also  seest  on  the  day  is  lucky.'  It  was 
quite  otherwise  with  the  unlucky  and  dangerous  days, 
which  imposed  so  many  and  such  great  limitations  on 
people  that  those  who  wished  to  be  prudent  were  al- 
ways obliged  to  bear  them  in  mind  when  determining 
on  any  course  of  action.  Certain  conditions  were  easy 
to  carry  out.  Music  and  singing  were  to  be  avoided 
on  the  14th  Tybi,  the  day  of  the  mourning  of  Osiris, 
and  no  one  was  allowed  to  wash  on  the  16th  Tybi; 
whilst  the  name  of  Set  might  not  be  pronounced  on  the 
24th  of  Pharmuthi.  Fish  was  forbidden  on  certain 
days ;  and  what  was  still  more  difficult  in  a  country 
so  rich  in  mice,  on  the  12  th  of  Tybi  no  mouse  might 
be  seen.  The  most  tiresome  prohibitions,  however, 
were  those  which  occurred  not  infrequently,  namely, 
those  concerning  work  and  going  out:  for  instance, 
four  times  in  Paophi  the  people  had  to  'do  nothing 
at  all,'  and  five  times  to  sit  the  whole  day  or  half 
the  day  in  the  house;  and  the  same  rule  had  to  be 

45 


A   HISTORY   OF   SCIENCE 

observed  each  month.  It  was  impossible  to  rejoice 
if  a  child  was  born  on  the  23d  of  Thoth;  the  par- 
ents knew  it  could  not  live.  Those  born  on  the 
20th  of  Choiakh  would  become  blind,  and  those  born 
on  the  3d  of  Choiakh,  deaf." 

CHARMS    AND    INCANTATIONS 

Where  such  conceptions  as  these  pertained,  it  goes 
without  saying  that  charms  and  incantations  intended 
to  break  the  spell  of  the  unlucky  omens  were  equally 
prevalent.  Such  incantations  consisted  usually  of  the 
recitation  of  certain  phrases  based  originally,  it  would 
appear,  upon  incidents  in  the  history  of  the  gods.  The 
words  which  the  god  had  spoken  in  connection  with 
some  lucky  incident  would,  it  was  thought,  prove  effec- 
tive now  in  bringing  good  luck  to  the  human  suppli- 
cant— that  is  to  say,  the  magician  hoped  through  re- 
peating the  words  of  the  god  to  exercise  the  magic  pow- 
er of  the  god.  It  was  even  possible,  with  the  aid  of  the 
magical  observances,  partly  to  balk  fate  itself.  Thus 
the  person  predestined  through  birth  on  an  unlucky 
day  to  die  of  a  serpent  bite  might  postpone  the  time 
of  this  fateful  visitation  to  extreme  old  age.  The  like 
uncertainty  attached  to  those  spells  which  one  person 
was  supposed  to  be  able  to  exercise  over  another.  It 
was  held,  for  example,  that  if  something  belonging  to 
an  individual,  such  as  a  lock  of  hair  or  a  paring  of  the 
nails,  could  be  secured  and  incorporated  in  a  waxen 
figure,  this  figure  would  be  intimately  associated  with 
the  personality  of  that  individual.  An  enemy  might 
thus  secure  occult  power  over  one ;  any  indignity  prac- 
tised upon  the  waxen  figure  would  result  in  like  injury 

46 


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z 

o 

EGYPTIAN   SCIENCE 

to  its  human  prototype.  If  the  figure  were  bruised 
or  beaten,  some  accident  would  overtake  its  double; 
if  the  image  were  placed  over  a  fire,  the  human  being 
would  fall  into  a  fever,  and  so  on.  But,  of  course, 
such  mysterious  evils  as  these  would  be  met  and  com- 
bated by  equally  mysterious  processes;  and  so  it  was 
that  the  entire  art  of  medicine  was  closely  linked  with 
magical  practices.  It  was  not,  indeed,  held,  according 
to  Maspero,  that  the  magical  spells  of  enemies  were  the 
sole  sources  of  human  ailments,  but  one  could  never 
be  sure  to  what  extent  such  spells  entered  into  the 
affliction;  and  so  closely  were  the  human  activities 
associated  in  the  mind  of  the  Egyptian  with  one  form 
or  another  of  occult  influences  that  purely  physical 
conditions  were  at  a  discount.  In  the  later  times,  at 
any  rate,  the  physician  was  usually  a  priest,  and  there 
was  a  close  association  between  the  material  and 
spiritual  phases  of  therapeutics.  Erman4  tells  us 
that  the  following  formula  had  to  be  recited  at  the 
preparation  of  all  medicaments:  "That  Isis  might 
make  free,  make  free.  That  Isis  might  make  Horus 
free  from  all  evil  that  his  brother  Set  had  done  to  him 
when  he  slew  his  father,  Osiris.  O  Isis,  great  enchant- 
ress, free  me,  release  me  from  all  evil  red  things,  from 
the  fever  of  the  god,  and  the  fever  of  the  goddess,  from 
death  and  death  from  pain,  and  the  pain  which  comes 
over  me;  as  thou  hast  freed,  as  thou  hast  released  thy 
son  Horus,  whilst  I  enter  into  the  fire  and  come  forth 
from  the  water,"  etc.  Again,  when  the  invalid  took 
the  medicine,  an  incantation  had  to  be  said  which  be- 
gan thus : "  Come  remedy,  come  drive  it  out  of  my  heart,  , 
out  of  these  limbs  strong  in  magic  power  with  the 

47 


A   HISTORY   OF   SCIENCE 

remedy."  He  adds:  "There  may  have  been  a  few 
rationalists  amongst  the  Egyptian  doctors,  for  the 
number  of  magic  formulae  varies  much  in  the  different 
books.  The  book  that  we  have  specially  taken  for  a 
foundation  for  this  account  of  Egyptian  medicine — 
the  great  papyrus  of  the  eighteenth  dynasty  edited  by 
Ebers5 — contains,  for  instance,  far  fewer  exorcisms  than 
some  later  writings  with  similar  contents,  probably  be- 
cause the  doctor  who  compiled  this  book  of  recipes 
from  older  sources  had  very  little  liking  for  magic." 

It  must  be  understood,  however — indeed,  what  has 
just  been  said  implies  as  much — that  the  physician  by 
no  means  relied  upon  incantations  alone;  on  the  con- 
trary, he  equipped  himself  with  an  astonishing  variety 
of  medicaments.  He  had  a  particular  fondness  for 
what  the  modern  physician  speaks  of  as  a  "  shot-gun" 
prescription — one  containing  a  great  variety  of  in- 
gredients. Not  only  did  herbs  of  many  kinds  enter 
into  this,  but  such  substances  as  lizard's  blood,  the 
teeth  of  swine,  putrid  meat,  the  moisture  from  pigs' 
ears,  boiled  horn,  and  numerous  other  even  more  re- 
pellent ingredients.  Whoever  is  familiar  with  the 
formulae  employed  by  European  physicians  even  so 
recently  as  the  eighteenth  century  will  note  a  striking 
similarity  here.  Erman  points  out  that  the  modern 
Egyptian  even  of  this  day  holds  closely  to  many  of  the 
practices  of  his  remote  ancestor.  In  particular,  the 
efficacy  of  the  beetle  as  a  medicinal  agent  has  stood 
the  test  of  ages  of  practice.  "Against  all  kinds  of 
witchcraft,"  says  an  ancient  formula,  "a  great  scara- 
baeus  beetle ;  cut  off  his  head  and  wings,  boil  him ;  put 
him  in  oil  and  lay  him  out;  then  cook  his  head  and 

48 


EGYPTIAN   SCIENCE 

wings,  put  them  in  snake  fat,  boil,  and  let  the  patient 
drink  the  mixture."  The  modern  Egyptian,  says  Er- 
man,  uses  almost  precisely  the  same  recipe,  except  that 
the  snake  fat  is  replaced  by  modern  oil. 

In  evidence  of  the  importance  which  was  attached 
to  practical  medicine  in  the  Egypt  of  an  early  day,  the 
names  of  several  physicians  have  come  down  to  us 
from  an  age  which  has  preserved  very  few  names 
indeed,  save  those  of  kings.  In  reference  to  this  Er- 
man  says6:  "We  still  know  the  names  of  some  of  the 
early  body  physicians  of  this  time ;  Sechmetna'eonch, 
'chief  physician  of  the  Pharaoh,'  and  Nesmenan  his 
chief,  the  '  superintendent  of  the  physicians  of  the  Pha- 
raoh.' The  priests  also  of  the  lioness-headed  goddess 
Sechmet  seem  to  have  been  famed  for  their  medical  wis- 
dom, whilst  the  son  of  this  goddess,  the  demi-god  Imho- 
tep,  was  in  later  times  considered  to  be  the  creator  of 
medical  knowledge.  These  ancient  doctors  of  the  New 
Empire  do  not  seem  to  have  improved  upon  the  older 
conceptions  about  the  construction  of  the  human  body." 

As  to  the  actual  scientific  attainments  of  the  Egyp- 
tian physician,  it  is  difficult  to  speak  with  precision. 
Despite  the  cumbersome  formulas  and  the  grotesque 
incantations,  we  need  not  doubt  that  a  certain  prac- 
tical value  attended  his  therapeutics.  He  practised  al- 
most pure  empiricism,  however,  and  certainly  it  must 
have  been  almost  impossible  to  determine  which  ones, 
if  any,  of  the  numerous  ingredients  of  the  prescription 
had  real  efficacy. 

The  practical  anatomical  knowledge  of  the  physi- 
cian, there  is  every  reason  to  believe,  was  extremely 
limited.     At  first  thought  it  might  seem  that  the  prac- 

VOL.  I. — 4  49 


A   HISTORY   OF   SCIENCE 

tice  of  embalming  would  have  led  to  the  custom  of  dis- 
secting human  bodies,  and  that  the  Egyptians,  as  a 
result  of  this,  would  have  excelled  in  the  knowledge 
of  anatomy.  But  the  actual  results  were  rather  the 
reverse  of  this.  Embalming  the  dead,  it  must  be  re- 
called, was  a  purely  religious  observance.  It  took 
place  under  the  superintendence  of  the  priests,  but  so 
great  was  the  reverence  for  the  human  body  that  the 
priests  themselves  were  not  permitted  to  make  the 
abdominal  incision  which  was  a  necessary  preliminary 
of  the  process.  This  incision,  as  we  are  informed  by 
both  Herodotus7  and  Diodorus8,was  made  by  a  special 
officer,  whose  status,  if  we  may  believe  the  explicit 
statement  of  Diodorus,  was  quite  comparable  to  that 
of  the  modern  hangman.  The  paraschistas,  as  he  was 
called,  having  performed  his  necessary  but  obnoxious 
function,  with  the  aid  of  a  sharp  Ethiopian  stone,  re- 
tired hastily,  leaving  the  remaining  processes  to  the 
priests.  These,  however,  confined  their  observations 
to  the  abdominal  viscera;  under  no  consideration  did 
they  make  other  incisions  in  the  body.  It  follows, 
therefore,  that  their  opportunity  for  anatomical  ob- 
servations was  most  limited. 

Since  even  the  necessary  mutilation  inflicted  on  the 
corpse  was  regarded  with  such  horror,  it  follows  that 
anything  in  the  way  of  dissection  for  a  less  sacred  pur- 
pose was  absolutely  prohibited.  Probably  the  same 
prohibition  extended  to  a  large  number  of  animals, 
since  most  of  these  were  held  sacred  in  one  part  of 
Egypt  or  another.  Moreover,  there  is  nothing  in  what 
we  know  of  the  Egyptian  mind  to  suggest  the  proba- 
bility that  any  Egyptian  physician  would  make  exten- 

5o 


EGYPTIAN   SCIENCE 

sive  anatomical  observations  for  the  love  of  pure 
knowledge.  All  Egyptian  science  is  eminently  practi- 
cal. If  we  think  of  the  Egyptian  as  mysterious,  it  is  be- 
cause of  the  superstitious  observances  that  we  every- 
where associate  with  his  daily  acts;  but  these,  as  we 
have  already  tried  to  make  clear,  were  really  based  on 
scientific  observations  of  a  kind,  and  the  attempt  at 
true  inferences  from  these  observations.  But  whether 
or  not  the  Egyptian  physician  desired  anatomical 
knowledge,  the  results  of  his  inquiries  were  certainly 
most  meagre.  The  essentials  of  his  system  had  to  do 
with  a'  series  of  vessels,  alleged  to  be  twenty-two  or 
twenty-four  in  number,  which  penetrated  the  head  and 
were  distributed  in  pairs  to  the  various  members  of  the 
body,  and  which  were  vaguely  thought  of  as  carriers  of 
water,  air,  excretory  fluids,  etc.  Yet  back  of  this  vague- 
ness, as  must  not  be  overlooked,  there  was  an  all-essen- 
tial recognition  of  the  heart  as  the  central  vascular 
organ.  The  heart  is  called  the  beginning  of  all  the 
members.  Its  vessels,  we  are  told,  "  lead  to  all  the  mem- 
bers ;  whether  the  doctor  lays  his  finger  on  the  forehead, 
on  the  back  of  the  head,  on  the  hands,  on  the  place  of 
the  stomach  ( ?),  on  the  arms,  or  on  the  feet,  everywhere 
he  meets  with  the  heart,  because  its  vessels  lead  to  all 
the  members."9  This  recognition  of  the  pulse  must 
be  credited  to  the  Egyptian  physician  as  a  piece  of 
practical  knowledge,  in  some  measure  off-setting  the 
vagueness  of  his  anatomical  theories. 

ABSTRACT   SCIENCE 

But,  indeed,  practical  knowledge  was,  as  has  been 
said  over  and  over,  the  essential  characteristic  of  Egyp- 

5i 


A   HISTORY   OF   SCIENCE 

tian  science.  Yet  another  illustration  of  this  is  fur- 
nished us  if  we  turn  to  the  more  abstract  departments 
of  thought  and  inquire  what  were  the  Egyptian  at- 
tempts in  such  a  field  as  mathematics.  The  answer 
does  not  tend  greatly  to  increase  our  admiration  for 
the  Egyptian  mind.  We  are  led  to  see,  indeed,  that 
the  Egyptian  merchant  was  able  to  perform  all  the 
computations  necessary  to  his  craft,  but  we  are  forced 
to  conclude  that  the  knowledge  of  numbers  scarcely 
extended  beyond  this,  and  that  even  here  the  methods 
of  reckoning  were  tedious  and  cumbersome.  Our 
knowledge  of  the  subject  rests  largely  upon  the  so- 
called  papyrus  Rhind,10  which  is  a  sort  of  mythological 
hand-book  of  the  ancient  Egyptians.  Analyzing  this 
document,  Professor  Erman  concludes  that  the  knowl- 
edge of  the  Egyptians  was  adequate  to  all  practical 
requirements.  Their  mathematics  taught  them  "how 
in  the  exchange  of  bread  for  beer  the  respective  value 
was  to  be  determined  when  converted  into  a  quantity 
of  corn ;  how  to  reckon  the  size  of  a  field ;  how  to  deter- 
mine how  a  given  quantity  of  corn  would  go  into  a 
granary  of  a  certain  size,"  and  like  every-day  prob- 
lems. Yet  they  were  obliged  to  make  some  of  their 
simple  computations  in  a  very  roundabout  way.  It 
would  appear,  for  example,  that  their  mental  arith- 
metic did  not  enable  them  to  multiply  by  a  number 
larger  than  two,  and  that  they  did  not  reach  a  clear 
conception  of  complex  fractional  numbers.  They  did, 
indeed,  recognize  that  each  part  of  an  object  divided 
into  10  pieces  became  ^  of  that  object;  they  even 
grasped  the  idea  of  f ,  this  being  a  conception  easily 
visualized ;  but  they  apparently  did  not  visualize  such, 

52 


EGYPTIAN    SCIENCE 

a  conception  as  ^,  except  in  the  crude  form  of  -^  plus 
-3*5  plus  f^.  Their  entire  idea  of  division  seems  de- 
fective. They  viewed  the  subject  from  the  more  ele- 
mentary stand -point  of  multiplication.  Thus,  in  or- 
der to  find  out  how  many  times  7  is  contained  in  77, 
an  existing  example  shows  that  the  numbers  repre- 
senting 1  times  7,  2  times  7,  4  times  7,  8  times  7  were 
set  down  successively  and  various  experimental  ad- 
ditions made  to  find  out  which  sets  of  these  numbers 
aggregated  77. 


■I 

7 

■2 

14 

4 

28 

■8 

56 

A  line  before  the  first,  second,  and  fourth  of  these  num- 
bers indicated  that  it  is  necessary  to  multiply  7  by 
1  plus  2  plus  8 — that  is,  by  11,  in  order  to  obtain  7  7 ; 
that  is  to  say,  7  goes  11  times  in  77.  All  this  seems 
very  cumbersome  indeed,  yet  we  must  not  overlook 
the  fact  that  the  process  which  goes  on  in  our  own 
minds  in  performing  such  a  problem  as  this  is  precisely 
similar,  except  that  we  have  learned  to  slur  over  certain 
of  the  intermediate  steps  with  the  aid  of  a  memorized 
multiplication  table.  In  the  last  analysis,  division  is 
only  the  obverse  side  of  multiplication,  and  any  one 
who  has  not  learned  his  multiplication  table  is  reduced 
to  some  such  expedient  as  that  of  the  Egyptian.  In- 
deed, whenever  we  pass  beyond  the  range  of  our  mem- 
orized multiplication  table — which  for  most  of  us  ends 
with  the  twelves  —  the  experimental  character  of  the 
trial  multiplication  through  which  division  is  finally 
effected  does  not  so  greatly  differ  from  the  experi- 

53 


A   HISTORY   OF  SCIENCE 

mental  efforts  which  the  Egyptian  was  obliged  to  ap- 
ply to  smaller  numbers. 

Despite  his  defective  comprehension  of  fractions, 
the  Egyptian  was  able  to  work  out  problems  of  rela- 
tive complexity;  for  example,  he  could  determine  the 
answer  of  such  a  problem  as  this:  a  number  together 
with  its  fifth  part  makes  2 1 ;  what  is  the  number  ?  The 
process  by  which  the  Egyptian  solved  this  problem 
seems  very  cumbersome  to  any  one  for  whom  a  rudi- 
mentary knowledge  of  algebra  makes  it  simple,  yet  the 
method  which  we  employ  differs  only  in  that  we  are 
enabled,  thanks  to  our  hypothetical  x,  to  make  a  short 
cut,  and  the  essential  fact  must  not  be  overlooked  that 
the  Egyptian  reached  a  correct  solution  of  the  prob- 
lem. With  all  due  desire  to  give  credit,  however,  the 
fact  remains  that  the  Egyptian  was  but  a  crude  mathe- 
matician. Here,  as  elsewhere,  it  is  impossible  to  ad- 
mire him  for  any  high  development  of  theoretical 
science.  First,  last,  and  all  the  time,  he  was  practical, 
and  there  is  nothing  to  show  that  the  thought  of  science 
for  its  own  sake,  for  the  mere  love  of  knowing,  ever 
entered  his  head. 

In  general,  then,  we  must  admit  that  the  Egyptian 
had  not  progressed  far  in  the  hard  way  of  abstract 
thinking.  He  worshipped  everything  about  him  be- 
cause he  feared  the  result  of  failing  to  do  so.  He  em- 
balmed the  dead  lest  the  spirit  of  the  neglected  one 
might  come  to  torment  him.  Eye-minded  as  he  was, 
he  came  to  have  an  artistic  sense,  to  love  decorative 
effects.  But  he  let  these  always  take  precedence  over 
his  sense  of  truth;  as,  for  example,  when  he  modified 
his  lists  of  kings  at  Abydos  to  fit  the  space  which  the 

54 


EGYPTIAN    SCIENCE 

architect  had  left  to  be  filled;  he  had  no  historical 
sense  to  show  to  him  that  truth  should  take  precedence 
over  mere  decoration.  And  everywhere  he  lived  in 
the  same  happy-go-lucky  way.  He  loved  personal 
ease,  the  pleasures  of  the  table,  the  luxuries  of  life, 
games,  recreations,  festivals.  He  took  no  heed  for  the 
morrow,  except  as  the  morrow  might  minister  to  his 
personal  needs.  Essentially  a  sensual  being,  he  scarce- 
ly conceived  the  meaning  of  the  intellectual  life  in  the 
modern  sense  of  the  term.  He  had  perforce  learned 
some  things  about  astronomy,  because  these  were 
necessary  to  his  worship  of  the  gods ;  about  practical 
medicine,  because  this  ministered  to  his  material  needs ; 
about  practical  arithmetic,  because  this  aided  him  in 
every-day  affairs.  The  bare  rudiments  of  an  historical 
science  may  be  said  to  be  crudely  outlined  in  his  de- 
fective lists  of  kings.  But  beyond  this  he  did  not  go. 
Science  as  science,  and  for  its  own  sake,  was  unknown 
to  him.  He  had  gods  for  all  material  functions,  and 
festivals  in  honor  of  every  god ;  but  there  was  no  god- 
dess of  mere  wisdom  in  his  pantheon.  The  conception 
of  Minerva  was  reserved  for  the  creative  genius  of  an- 
other people. 


Ill 

SCIENCE  OF   BABYLONIA   AND   ASSYRIA 

THROUGHOUT  classical  antiquity  Egyptian  sci- 
ence was  famous.  We  know  that  Plato  spent 
some  years  in  Egypt  in  the  hope  of  penetrating  the 
alleged  mysteries  of  its  fabled  learning ;  and  the  story 
of  the  Egyptian  priest  who  patronizingly  assured 
Solon  that  the  Greeks  were  but  babes  was  quoted 
everywhere  without  disapproval.  Even  so  late  as  the 
time  of  Augustus,  we  find  Diodorus,  the  Sicilian,  look- 
ing back  with  veneration  upon  the  Oriental  learning, 
to  which  Pliny  also  refers  with  unbounded  respect. 
From  what  we  have  seen  of  Egyptian  science,  all  this 
furnishes  us  with  a  somewhat  striking  commentary 
upon  the  attainments  of  the  Greeks  and  Romans  them- 
selves. To  refer  at  length  to  this  would  be  to  antici- 
pate our  purpose ;  what  now  concerns  us  is  to  recall  that 
all  along  there  was  another  nation,  or  group  of  nations, 
that  disputed  the  palm  for  scientific  attainments. 
This  group  of  nations  found  a  home  in  the  valley  of 
the  Tigris  and  Euphrates.  Their  land  was  named 
Mesopotamia  by  the  Greeks,  because  a  large  part  of 
it  lay  between  the  two  rivers  just  mentioned.  The 
peoples  themselves  are  familiar  to  every  one  as  the 
Babylonians  and  the  Assyrians.  These  peoples  were 
of  Semitic  stock — allied,  therefore,  to  the  ancient  He- 

56 


SCIENCE  OF  BABYLONIA  AND  ASSYRIA 

brews  and  Phoenicians  and  of  the  same  racial  stem 
with  the  Arameans  and  Arabs. 

The  great  capital  of  the  Babylonians  during  the 
later  period  of  their  history  was  the  famed  city  of 
Babylon  itself ;  the  most  famous  capital  of  the  Assyr- 
ians was  Nineveh,  that  city  to  which,  as  every  Bible- 
student  will  recall,  the  prophet  Jonah  was  journeying 
when  he  had  a  much-exploited  experience,  the  record 
of  which  forms  no  part  of  scientific  annals.  It  was  the 
kings  of  Assyria,  issuing  from  their  palaces  in  Nineveh, 
who  dominated  the  civilization  of  Western  Asia  during 
the  heyday  of  Hebrew  history,  and  whose  deeds  are  so 
frequently  mentioned  in  the  Hebrew  chronicles.  Later 
on,  in  the  year  606  B.C.,  Nineveh  was  overthrown  by 
the  Medes  *  and  Babylonians.  The  famous  city  was 
completely  destroyed,  never  to  be  rebuilt.  Babylon, 
however,  though  conquered  subsequently  by  Cyrus 
and  held  in  subjection  by  Darius,2  the  Persian  kings, 
continued  to  hold  sway  as  a  great  world -capital  for 
some  centuries.  The  last  great  historical  event  that 
occurred  within  its  walls  was  the  death  of  Alexander 
the  Great,  which  took  place  there  in  the  year  322  B.C. 

In  the  time  of  Herodotus  the  fame  of  Babylon  was 
at  its  height,  and  the  father  of  history  has  left  us  a 
most  entertaining  account  of  what  he  saw  when  he 
visited  the  wonderful  capital.  Unfortunately,  Herod- 
otus was  not  a  scholar  in  the  proper  acceptance  of  the 
term.  He  probably  had  no  inkling  of  the  Babylonian 
language,  so  the  voluminous  records  of  its  literature 
were  entirely  shut  off  from  his  observation.  He 
therefore  enlightens  us  but  little  regarding  the  science 
of  the  Babylonians,  though  his  observations  on  their 

57 


A   HISTORY   OF   SCIENCE 

practical  civilization  give  us  incidental  references  of 
no  small  importance.  Somewhat  more  detailed  ref- 
erences to  the  scientific  attainments  of  the  Babylonians 
are  found  in  the  fragments  that  have  come  down  to  us 
of  the  writings  of  the  great  Babylonian  historian, 
Berosus,3  who  was  born  in  Babylon  about  330  B.C.,  and 
who  was,  therefore,  a  contemporary  of  Alexander  the 
Great.  But  the  writings  of  Berosus  also,  or  at  least 
such  parts  of  them  as  have  come  down  to  us,  leave 
very  much  to  be  desired  in  point  of  explicitness.  They 
give  some  glimpses  of  Babylonian  history,  and  they 
detail  at  some  length  the  strange  mythical  tales  of 
creation  that  entered  into  the  Babylonian  conception 
of  cosmogony — details  which  find  their  counterpart  in 
the  allied  recitals  of  the  Hebrews.  But  taken  all  in  all, 
the  glimpses  of  the  actual  state  of  Chaldean 4  learning, 
as  it  was  commonly  called,  amounted  to  scarcely  more 
than  vague  wonder -tales.  No  one  really  knew  just 
what  interpretation  to  put  upon  these  tales  until  the 
explorers  of  the  nineteenth  century  had  excavated  the 
ruins  of  the  Babylonian  and  Assyrian  cities,  bringing  to 
light  the  relics  of  their  wonderful  civilization.  But 
these  relics  fortunately  included  vast  numbers  of  writ- 
ten documents,  inscribed  on  tablets,  prisms,  and 
cylinders  of  terra-cotta.  When  nineteenth-century 
scholarship  had  penetrated  the  mysteries  of  the 
strange  script,  and  ferreted  out  the  secrets  of  an  un- 
known tongue,  the  world  at  last  was  in  possession  of 
authentic  records  by  which  the  traditions  regarding 
the  Babylonians  and  Assyrians  could  be  tested. 
Thanks  to  these  materials,  a  new  science  commonly 
spoken  of  as  Assyriology  came  into  being,  and  a  most 

58 


SCIENCE  OF  BABYLONIA  AND  ASSYRIA 

important  chapter  of  human  history  was  brought  to 
light.  It  became  apparent  that  the  Greek  ideas  con- 
cerning Mesopotamia,  though  vague  in  the  extreme, 
were  founded  on  fact.  No  one  any  longer  questions 
that  the  Mesopotamian  civilization  was  fully  on  a  par 
with  that  of  Egypt;  indeed,  it  is  rather  held  that  supe- 
riority lay  with  the  Asiatics.  Certainly,  in  point  of 
purely  scientific  attainments,  the  Babylonians  passed 
somewhat  beyond  their  Egyptian  competitors.  All 
the  evidence  seems  to  suggest  also  that  the  Babylonian 
civilization  was  even  more  ancient  than  that  of  Egypt. 
The  precise  dates  are  here  in  dispute ;  nor  for  our  pres- 
ent purpose  need  they  greatly  concern  us.  But  the 
Assyrio-Babylonian  records  have  much  greater  his- 
torical accuracy  as  regards  matters  of  chronology  than 
have  the  Egyptian,  and  it  is  believed  that  our  knowl- 
edge of  the  early  Babylonian  history  is  carried  back, 
with  some  certainty,  to  King  Sargon  of  Agade,5  for 
whom  the  date  3800  B.C.  is  generally  accepted;  while 
somewhat  vaguer  records  give  us  glimpses  of  periods 
as  remote  as  the  sixth,  perhaps  even  the  seventh  or 
eighth  millenniums  before  our  era. 

At  a  very  early  period  Babylon  itself  was  not  a  cap- 
ital and  Nineveh  had  not  come  into  existence.  The 
important  cities,  such  as  Nippur  and  Shirpurla,  were 
situated  farther  to  the  south.  It  is  on  the  site  of  these 
cities  that  the  recent  excavations  have  been  made, 
such  as  those  of  the  University  of  Pennsylvania  ex- 
peditions at  Nippur,6  which  are  giving  us  glimpses  into 
remoter  recesses  of  the  historical  period. 

Even  if  we  disregard  the  more  problematical  early 
dates,  we  are  still  concerned  with  the  records  of  a  civ- 

59 


A    HISTORY    OF   SCIENCE 

ilization  extending  unbroken  throughout  a  period,  of 
about  four  thousand  years;  the  actual  period  is  in  all 
probability  twice  or  thrice  that.  Naturally  enough, 
the  current  of  history  is  not  an  unbroken  stream 
throughout  this  long  epoch.  It  appears  that  at  least 
two  utterly  different  ethnic  elements  are  involved.  A 
preponderance  of  evidence  seems  to  show  that  the 
earliest  civilized  inhabitants  of  Mesopotamia  were  not 
Semitic,  but  an  alien  race,  which  is  now  commonly 
spoken  of  as  Sumerian.  This  people,  of  whom  we 
catch  glimpses  chiefly  through  the  records  of  its  suc- 
cessors, appears  to  have  been  subjugated  or  over- 
thrown by  Semitic  invaders,  who,  coming  perhaps 
from  Arabia  (their  origin  is  in  dispute) ,  took  possession 
of  the  region  of  the  Tigris  and  Euphrates,  learned 
from  the  Sumerians  many  of  the  useful  arts,  and, 
partly  perhaps  because  of  their  mixed  lineage,  were 
enabled  to  develop  the  most  wonderful  civilization 
of  antiquity.  Could  we  analyze  the  details  of  this 
civilization  from  its  earliest  to  its  latest  period  we 
should  of  course  find  the  same  changes  which  always 
attend  ■  racial  progress  and  decay.  We  should  then 
be  able,  no  doubt,  to  speak  of  certain  golden  epochs 
and  their  periods  of  decline.  To  a  certain  meagre 
extent  we  are  able  to  do  this  now.  We  know,  for  ex- 
ample, that  King  Khammurabi,  who  lived  about  2200 
b.c,  was  a  great  law-giver,  the  ancient  prototype  of 
Justinian;  and  the  epochs  of  such  Assyrian  kings  as 
Sargon  II.,  Asshurnazirpal,  Sennacherib,  and  Asshur- 
banapal  stand  out  with  much  distinctness.  Yet,  as  a 
whole,  the  record  does  not  enable  us  to  trace  with 
clearness  the  progress  of  scientific  thought.     At  best 

60 


SCIENCE  OF  BABYLONIA  AND  ASSYRIA 

we  can  gain  fewer  glimpses  in  this  direction  than  in  al- 
most any  other,  for  it  is  the  record  of  war  and  conquest 
rather  than  of  the  peaceful  arts  that  commanded  the 
attention  of  the  ancient  scribe.  So  in  dealing  with  the 
scientific  achievements  of  these  peoples,  we  shall  per- 
force consider  their  varied  civilizations  as  a  unity,  and 
attempt,  as  best  we  may,  to  summarize  their  achieve- 
ments as  a  whole.  For  the  most  part,  we  shall  not  at- 
tempt to  discriminate  as  to  what  share  in  the  final 
product  was  due  to  Sumerian,  what  to  Babylonian,  and 
what  to  Assyrian.  We  shall  speak  of  Babylonian  sci- 
ence as  including  all  these  elements ;  and  drawing  our 
information  chiefly  from  the  relatively  late  Assyrian 
and  Babylonian  sources,  which,  therefore,  represent 
the  culminating  achievements  of  all  these  ages  „of  ef- 
fort, we  shall  attempt  to  discover  what  was  the  actual 
status  of  Mesopotamian  science  at  its  climax.  In  so  far 
as  we  succeed,  we  shall  be  able  to  judge  what  scientific 
heritage  Europe  received  from  the  Orient;  for  in  the 
records  of  Babylonian  science  we  have  to  do  with  the 
Eastern  mind  at  its  best.  Let  us  turn  to  the  specific 
inquiry  as  to  the  achievements  of  the  Chaldean  scien- 
tist whose  fame  so  dazzled  the  eyes  of  his  contem- 
poraries of  the  classic  world. 

BABYLONIAN   ASTRONOMY 

Our  first  concern  naturally  is  astronomy,  this  being 
here,  as  in  Egypt,  the  first-born  and  the  most  important 
of  the  sciences.  The  fame  of  the  Chaldean  astronomer 
was  indeed  what  chiefly  commanded  the  admiration  of 
the  Greeks,  and  it  was  through  the  results  of  astronom- 
ical observations  that  Babylonia  transmitted  her  most 

61 


A   HISTORY    OF   SCIENCE 

important  influences  to  the  Western  world.  "  Our  di- 
vision of  time  is  of  Babylonian  origin,"  says  Hommel;7 
"  to  Babylonia  we  owe  the  week  of  seven  days,  with  the 
names  of  the  planets  for  the  days  of  the  week,  and  the 
division  into  hours  and  months."  Hence  the  almost 
personal  interest  which  we  of  to-day  must  needs  feel 
in  the  efforts  of  the  Babylonian  star-gazer. 

It  must  not  be  supposed,  however,  that  the  Chal- 
dean astronomer  had  made  any  very  extraordinary 
advances  upon  the  knowledge  of  the  Egyptian  "  watch- 
ers of  the  night."  After  all,  it  required  patient  ob- 
servation rather  than  any  peculiar  genius  in  the  ob- 
server to  note  in  the  course  of  time  such  broad  as- 
tronomical conditions  as  the  regularity  of  the  moon's 
phases,  and  the  relation  of  the  lunar  periods  to  the 
longer  periodical  oscillations  of  the  sun.  Nor  could 
the  curious  wanderings  of  the  planets  escape  the  at- 
tention of  even  a  moderately  keen  observer.  The 
chief  distinction  between  the  Chaldean  and  Egyptian 
astronomers  appears  to  have  consisted  in  the  relative 
importance  they  attached  to  various  of  the  phenomena 
which  they  both  observed.  The  Egyptian,  as  we  have 
seen,  centred  his  attention  upon  the  sun.  That  lumi- 
nary was  the  abode  of  one  of  his  most  important  gods. 
His  worship  was  essentially  solar.  The  Babylonian, 
on  the  other  hand,  appears  to  have  been  peculiarly  im- 
pressed with  the  importance  of  the  moon.  He  could 
not,  of  course,  overlook  the  attention-compelling  fact 
of  the  solar  year;  but  his  unit  of  time  was  the  lunar 
period  of  thirty  days,  and  his  year  consisted  of  twelve 
lunar  periods,  or  360  days.  He  was  perfectly  aware, 
however,  that  this  period  did  not  coincide  with  the 

62 


p 

a 

t3 

«i 

"-i 

H 

rrr 

a 

w 

ti 

a 

o 

Ss 

a 

&   2 


SCIENCE  OF  BABYLONIA  AND  ASSYRIA 

actual  year;  but  the  relative  unimportance  which  he 
ascribed  to  the  solar  year  is  evidenced  by  the  fact  that 
he  interpolated  an  added  month  to  adjust  the  calendar 
only  once  in  six  years.  Indeed,  it  would  appear  that 
the  Babylonians  and  Assyrians  did  not  adopt  precisely 
the  same  method  of  adjusting  the  calendar,  since  the 
Babylonians  had  two  intercular  months  called  Elul  and 
Adar,  whereas  the  Assyrians  had  only  a  single  such 
month,  called  the  second  Adar.8  (The  Ve'Adar  of  the 
Hebrews.)  This  diversity  further  emphasizes  the  fact 
that  it  was  the  lunar  period  which  received  chief  at- 
tention, the  adjustment  of  this  period  with  the  solar 
seasons  being  a  necessary  expedient  of  secondary  im- 
portance. It  is  held  that  these  lunar  periods  have 
often  been  made  to  do  service  for  years  in  the  Baby- 
lonian computations  and  in  the  allied  computations 
of  the  early  Hebrews.  The  lives  of  the  Hebrew  pa- 
triarchs, for  example,  as  recorded  in  the  Bible,  are  per- 
haps reckoned  in  lunar  "years."  Divided  by  twelve, 
the  "years"  of  Methuselah  accord  fairly  with  the  usual 
experience  of  mankind. 

Yet,  on  the  other  hand,  the  convenience  of  the  solar 
year  in  computing  long  periods  of  time  was  not  un- 
recognized, since  this  period  is  utilized  in  reckoning  the 
reigns  of  the  Assyrian  kings.  It  may  be  added  that 
the  reign  of  a  king  "  was  not  reckoned  from  the  day  of 
his  accession,  but  from  the  Assyrian  new  year's  day, 
either  before  or  after  the  day  of  accession.  There 
doe's  not  appear  to  have  been  any  fixed  rule  as  to 
which  new  year's  day  should  be  chosen ;  but  from  the 
number  of  known  cases,  it  appears  to  have  been  the 
general  practice  to  count  the  reigning  years  from  the 

63 


A    HISTORY   OF   SCIENCE 

new  year's  day  nearest  the  accession,  and  to  call  the 
period  between  the  accession  day  and  the  first  new 
year's  day  'the  beginning  of  the  reign,'  when  the  year 
from  the  new  year's  day  was  called  the  first  year,  and 
the  following  ones  were  brought  successively  from  it. 
Notwithstanding,  in  the  dates  of  several  Assyrian  and 
Babylonian  sovereigns  there  are  cases  of  the  year  of 
accession  being  considered  as  the  first  year,  thus  giving 
two  reckonings  for  the  reigns  of  various  monarchs, 
among  others,  Shalmaneser,  Sennacherib,  Nebuchad- 
rezzar." 9  This  uncertainty  as  to  the  years  of  reckon- 
ing again  emphasizes  the  fact  that  the  solar  year  did 
not  have  for  the  Assyrian  chronology  quite  the  same 
significance  that  it  has  for  us. 

The  Assyrian  month  commenced  on  the  evening 
when  the  new  moon  was  first  observed,  or,  in  case  the 
moon  was  not  visible,  the  new  month  started  thirty 
days  after  the  last  month.  Since  the  actual  lunar 
period  is  about  twenty-nine  and  one-half  days,  a  prac- 
tical adjustment  was  required  between  the  months 
themselves,  and  this  was  probably  effected  by  counting 
alternate  months  as  only  29  days  in  length.  Mr.  R. 
Campbell  Thompson10  is  led  by  his  studies  of  the  astro- 
logical tablets  to  emphasize  this  fact.  He  believes 
that  "  the  object  of  the  astrological  reports  which  re- 
lated to  the  appearance  of  the  moon  and  sun  was  to  help 
determine  and  foretell  the  length  of  the  lunar  month." 
Mr.  Thompson  believes  also  that  there  is  evidence  to 
show  that  the  interculary  month  was  added  at  a  period 
less  than  six  years.  In  point  of  fact,  it  does  not  ap- 
pear to  be  quite  clearly  established  as  to  precisely  how 
the  adjustment  of  days  with  the  lunar  months,  and 

64 


CHALDEAN    MAP    OF    THE    WORLD 
(From  a  drawing  by  Faucher-Gudin  in  Maspero's  Dawn  of  Civilization.) 


SCIENCE  OF  BABYLONIA  AND  ASSYRIA 

lunar  months  with  the  solar  year,  was  effected.  It  is 
clear,  however,  according  to  Smith,  "  that  the  first  28 
days  of  every  month  were  divided  into  four  weeks  of 
seven  days  each ;  the  seventh,  fourteenth,  twenty-first, 
twenty  -  eighth  days  respectively  being  Sabbaths,  and 
that  there  was  a  general  prohibition  of  work  on  these 
days."  Here,  of  course,  is  the  foundation  of  the  Hebrew 
system  of  Sabbatical  days  which  we  have  inherited. 
The  sacredness  of  the  number  seven  itself — the  belief  in 
which  has  not  been  quite  shaken  off  even  to  this  day 
— was  deduced  by  the  Assyrian  astronomer  from  his  ob- 
servation of  the  seven  planetary  bodies — namely,  Sin 
(the  moon),  Samas  (the  sun),  Umunpawddu  (Jupiter), 
Dilbat  (Venus),  Kaimanu  (Saturn),  Gudud  (Mercury), 
Mustabarru-mutanu  (Mars).11  Twelve  lunar  periods, 
making  up  approximately  the  solar  year,  gave  peculiar 
importance  to  the  number  twelve  also.  Thus  the 
zodiac  was  divided  into  twelve  signs  which  astrono- 
mers of  all  subsequent  times  have  continued  to  recog- 
nize; and  the  duodecimal  system  of  counting  took  pre- 
cedence with  the  Babylonian  mathematicians  over  the 
more  primitive  and,  as  it  seems  to  us,  more  satisfactory 
decimal  system. 

Another  discrepancy  between  the  Babylonian  and 
Egyptian  years  appears  in  the  fact  that  the  Babylonian 
new  year  dates  from  about  the  period  of  the  vernal 
equinox  and  not  from  the  solstice.  Lockyer  associates 
this  with  the  fact  that  the  periodical  inundation  of  the 
Tigris  and  Euphrates  occurs  about  the  equinoctial 
period,  whereas,  as  we  have  seen,  the  Nile  flood  comes 
at  the  time  of  the  solstice.  It  is  but  natural  that  so 
important  a  phenomenon  as  the  Nile  flood  should  make 
s  65 


A   HISTORY   OF   SCIENCE 

a  strong  impression  upon  the  minds  of  a  people  living 
in  a  valley.  The  fact  that  occasional  excessive  inun- 
dations have  led  to  most  disastrous  results  is  evidenced 
in  the  incorporation  of  stories  of  the  almost  total  de- 
struction of  mankind  by  such  floods  among  the  myth 
tales  of  all  peoples  who  reside  in  valley  countries.  The 
flooding  of  the  Tigris  and  Euphrates  had  not,  it  is  true, 
quite  the  same  significance  for  the  Mesopotamians  that 
the  Nile  flood  had  for  the  Egyptians.  Nevertheless  it 
was  a  most  important  phenomenon,  and  may  very 
readily  be  imagined  to  have  been  the  most  tangible 
index  to  the  seasons.  But  in  recognizing  the  time  of 
the  inundations  and  the  vernal  equinox,  the  Assyrians 
did  not  dethrone  the  moon  from  its  accustomed  pre- 
cedence, for  the  year  was  reckoned  as  commencing  not 
precisely  at  the  vernal  equinox,  but  at  the  new  moon 
next  before  the  equinox. 

ASTROLOGY 

Beyond  marking  the  seasons,  the  chief  interests  that 
actuated  the  Babylonian  astronomer  in  his  observa- 
tions were  astrological.  After  quoting  Diodorus  to  the 
effect  that  the  Babylonian  priests  observed  the  position 
of  certain  stars  in  order  to  cast  horoscopes,  Thompson 
tells  us  that  from  a  very  early  day  the  very  name 
Chaldean  became  synonymous  with  magician.  He 
adds  that  "from  Mesopotamia,  by  way  of  Greece  and 
Rome,  a  certain  amount  of  Babylonian  astrology  made 
its  way  among  the  nations  of  the  west,  and  it  is  quite 
probable  that  many  superstitions  which  we  commonly 
record  as  the  peculiar  product  of  western  civilization 
took  their  origin  from  those  of  the  early  dwellers  on  the 

66 


SCIENCE  OF  BABYLONIA  AND  ASSYRIA 

alluvial  lands  of  Mesopotamia.  One  Assurbanipal, 
king  of  Assyria  B.C.  668-626,  added  to  trie  royal  library 
at  Nineveh  his  contribution  of  tablets,  which  included 
many  series  of  documents  which  related  exclusively 
to  the  astrology  of  the  ancient  Babylonians,  who  in 
turn  had  borrowed  it  with  modifications  from  the 
Sumerian  invaders  of  the  country.  Among  these  must 
be  mentioned  the  series  which  was  commonly  called 
'  the  Day  of  Bel,'  and  which  was  decreed  by  the  learned 
to  have  been  written  in  the  time  of  the  great  Sargon  I., 
king  of  Agade,  3800  b.c.  With  such  ancient  works  as 
these  to  guide  them,  the  profession  of  deducing  omens 
from  daily  events  reached  such  a  pitch  of  importance 
in  the  last  Assyrian  Empire  that  a  system  of  making 
periodical  reports  came  into  being.  By  these  the  king 
was  informed  of  all  the  occurrences  in  the  heavens  and 
on  earth,  and  the  results  of  astrological  studies  in  re- 
spect to  after  events.  The  heads  of  the  astrological 
profession  were  men  of  high  rank  and  position,  and 
their  office  was  hereditary.  The  variety  of  information 
contained  in  these  reports  is  best  gathered  from  the 
fact  that  they  were  sent  from  cities  as  far  removed 
from  each  other  as  Assur  in  the  north  and  Erech  in  the 
south,  and  it  can  only  be  assumed  that  they  were  de- 
spatched by  runners,  or  men  mounted  on  swift  horses. 
As  reports  also  came  from  Dilbat,  Kutha,  Nippur,  and 
Bursippa,  all  cities  of  ancient  foundation,  the  king  was 
probably  well  acquainted  with  the  general  course  of 
events  in  his  empire."  12 

From  certain  passages  in  the  astrological  tablets, 
Thompson  draws  the  interesting  conclusion  that  the 
Chaldean   astronomers   were   acquainted   with    some 

67 


A   HISTORY   OF   SCIENCE 

kind  of  a  machine  for  reckoning  time.  He  finds  in  one 
of  the  tablets  a  phrase  which  he  interprets  to  mean 
measure-governor,  and  he  infers  from  this  the  existence 
of  a  kind  of  a  calculator.  He  calls  attention  also  to  the 
fact  that  Sextus  Empiricus 13  states  that  the  clepsydra 
was  known  to  the  Chaldeans,  and  that  Herodotus  as- 
serts that  the  Greeks  borrowed  certain  measures  of  time 
from  the  Babylonians.  He  finds  further  corroboration 
in  the  fact  that  the  Babylonians  had  a  time-measure  by 
which  they  divided  the  day  and  the  night ;  a  measure 
called  kasbu,  which  contained  two  hours.  In  a  report  re- 
lating to  the  day  of  the  vernal  equinox,  it  is  stated  that 
there  are  six  kasbu  of  the  day  and  six  kasbu  of  the  night. 

While  the  astrologers  deduced  their  omens  from  all 
the  celestial  bodies  known  to  them,  they  chiefly  gave 
attention  to  the  moon,  noting  with  great  care  the  shape 
of  its  horns,  and  deducing  such  a  conclusion  as  that 
"  if  the  horns  are  pointed  the  king  will  overcome  what- 
ever he  goreth,"  and  that  "  when  the  moon  is  low  at  its 
appearance,  the  submission  (of  the  people)  of  a  far 
country  will  come."  14  The  relations  of  the  moon  and 
sun  were  a  source  of  constant  observation,  it  being 
noted  whether  the  sun  and  moon  were  seen  together 
above  the  horizon;  whether  one  set  as  the  other  rose, 
and  the  like.  And  whatever  the  phenomena,  there  was 
always,  of  course,  a  direct  association  between  such 
phenomena  and  the  well-being  of  human  kind  —  in 
particular  the  king,  at  whose  instance,  and  doubtless 
at  whose  expense,  the  observations  were  carried  out. 

From  omens  associated  with  the  heavenly  bodies  it 
is  but  a  step  to  omens  based  upon  other  phenomena  of 
nature,  and  we  shall  see  in  a  moment  that  the'  Babylo- 

68 


Illiii 
liiill 


M&IwmM@S 


a  x 


3.      2     g 

-    2  o 


1 


■■NMi 


SCIENCE  OF  BABYLONIA  AND  ASSYRIA 

nian  prophets  made  free  use  of  their  opportunities  in 
this  direction  also.  But  before  we  turn  from  the  field 
of  astronomy,  it  will  be  well  to  inform  ourselves  as  to 
what  system  the  Chaldean  astronomer  had  invented  in 
explanation  of  the  mechanics  of  the  universe.  Our 
answer  to  this  inquiry  is  not  quite  as  definite  as  could 
be  desired,  the  vagueness  of  the  records,  no  doubt,  co- 
inciding with  the  like  vagueness  in  the  minds  of  the 
Chaldeans  themselves.  So  far  as  we  can  interpret  the 
somewhat  mystical  references  that  have  come  down 
to  us,  however,  the  Babylonian  cosmology  would  seem 
to  have  represented  the  earth  as  a  circular  plane  sur- 
rounded by  a  great  circular  river,  beyond  which  rose 
an  impregnable  barrier  of  mountains,  and  resting  upon 
an  infinite  sea  of  waters.  The  material  vault  of  the 
heavens  was  supposed  to  find  support  upon  the  outly- 
ing circle  of  mountains.  But  the  precise  mechanism 
through  which  the  observed  revolution  of  the  heavenly 
bodies  was  effected  remains  here,  as  with  the  Egyptian 
cosmology,  somewhat  conjectural.  The  simple  fact 
would  appear  to  be  that,  for  the  Chaldeans  as  for  the 
Egyptians,  despite  their  most  careful  observations  of 
the  tangible  phenomena  of  the  heavens,  no  really  sat- 
isfactory mechanical  conception  of  the  cosmos  was 
attainable.  We  shall  see  in  due  course  by  what  falter- 
ing steps  the  European  imagination  advanced  from 
the  crude  ideas  of  Egypt  and  Babylonia  to  the  relative- 
ly clear  vision  of  Newton  and  Laplace. 

CHALDEAN   MAGIC 

We  turn  now  from  the  field  of  the  astrologer  to  the 
closely  allied  province  of  Chaldean  magic — a  province 

69 


A   HISTORY   OF   SCIENCE 

which  includes  the  other;  which,  indeed,  is  so  all-en* 
compassing  as  scarcely  to  leave  any  phase  of  Baby- 
lonian thought  outside  its  bounds. 

The  tablets  having  to  do  with  omens,  exorcisms, 
and  the  like  magic  practices  make  up  an  astonishingly 
large  proportion  of  the  Babylonian  records.  In  view- 
ing them  it  is  hard  to  avoid  the  conclusion  that  the 
superstitions  which  they  evidenced  absolutely  domi- 
nated the  life  of  the  Babylonians  of  every  degree. 
Yet  it  must  not  be  forgotten  that  the  greatest  incon- 
sistencies everywhere  exist  between  the  superstitious 
beliefs  of  a  people  and  the  practical  observances  of 
that  people.  No  other  problem  is  so  difficult  for  the 
historian  as  that  which  confronts  him  when  he  en- 
deavors to  penetrate  the  mysteries  of  an  alien  religion ; 
and  when,  as  in  the  present  case,  the  superstitions  in- 
volved have  been  transmitted  from  generation  to  gen- 
eration, their  exact  practical  phases  as  interpreted  by 
any  particular  generation  must  be  somewhat  prob- 
lematical. The  tablets  upon  which  our  knowledge  of 
these  omens  is  based  are  many  of  them  from  the  li- 
braries of  the  later  kings  of  Nineveh;  but  the  omens 
themselves  are,  in  such  cases,  inscribed  in  the  original 
Accadian  form  in  which  they  have  come  down  from 
remote  ages,  accompanied  by  an  Assyrian  translation. 
Thus  the  superstitions  involved  had  back  of  them  hun- 
dreds of  years,  even  thousands  of  years,  of  precedent; 
and  we  need  not  doubt  that  the  ideas  with  which  they 
are  associated  were  interwoven  with  almost  every 
thought  and  deed  of  the  life  of  the  people.  Professor 
Sayce  assures  us  that  the  Assyrians  and  Babylonians 
counted  no  fewer  than  three  hundred  spirits  of  heaven, 

70 


SCIENCE  OF   BABYLONIA  AND  ASSYRIA 

and  six  hundred  spirits  of  earth.  "Like  the  Jews  of 
the  Talmud,"  he  says,  "they  believed  that  the  world 
was  swarming  with  noxious  spirits,  who  produced  the 
various  diseases  to  which  man  is  liable,  and  might  be 
swallowed  with  the  food  and  drink  which  support 
life."  Fox  Talbot  was  inclined  to  believe  that  exor- 
cisms were  the  exclusive  means  used  to  drive  away  the 
tormenting  spirits.  This  seems  unlikely,  considering 
the  uniform  association  of  drags  with  the  magical  prac- 
tices among  their  people.  Yet  there  is  certainly  a 
strange  silence  of  the  tablets  in  regard  to  medicine. 
Talbot  tells  us  that  sometimes  divine  images  were 
brought  into  the  sick-chamber,  and  written  texts 
taken  from  holy  books  were  placed  on  the  walls  and 
bound  around  the  sick  man's  members.  If  these 
failed,  recourse  was  had  to  the  influence  of  the  mamit, 
which  the  evil  powers  were  unable  to  resist.  On  a 
tablet,  written  in  the  Accadian  language  only,  the 
Assyrian  version  being  taken,  however,  was  found  the 
following : 

i.  Take  a  white  cloth.     In  it  place  the  mamit, 

2.  in  the  sick  man's  right  hand. 

3.  Take  a  black  cloth, 

4.  wrap  it  around  his  left  hand. 

5.  Then  all  the  evil  spirits  (a  long  list  of  them  is  given) 

6.  and  the  sins  which  he  has  committed 

7.  shall  quit  their  hold  of  him 

8.  and  shall  never  return. 

The  symbolism  of  the  black  cloth  in  the  left  hand 
seems  evident.  The  dying  man  repents  of  his  former 
evil  deeds,  and  he  puts  his  trust  in  holiness,  symbolized 
by  the  white  cloth  in  his  right  hand.  Then  follow 
some  obscure  lines  about  the  spirits : 

7i 


A   HISTORY   OF   SCIENCE 

i.  Their  heads  shall  remove  from  his  head. 

2.  Their  heads  shall  let  go  his  hands. 

3.  Their  feet  shall  depart  from  his  feet. 

Which  perhaps  may  be  explained  thus :  we  learn  from 
another  tablet  that  the  various  classes  of  evil  spirits 
troubled  different  parts  of  the  body ;  some  injured  the 
head,  some  the  hands  and  the  feet,  etc.,  therefore  the 
passage  before  may  mean  "  the  spirits  whose  power  is 
over  the  hand  shall  loose  their  hands  from  his,"  etc. 
"  But,"  concludes  Talbot,  "  I  can  offer  no  decided  opin- 
ion upon  such  obscure  points  of  their  superstition."  15 
In  regard  to  evil  spirits,  as  elsewhere,  the  number 
seven  had  a  peculiar  significance,  it  being  held  that 
that  number  of  spirits  might  enter  into  a  man  together. 
Talbot  has  translated 16  a  "  wild  chant"  which  he  names 
"The  Song  of  the  Seven  Spirits.'' 

1.  There  are  seven!     There  are  seven! 

2.  In  the  depths  of  the  ocean  there  are  seven! 

3.  In  the  heights  of  the  heaven  there  are  seven! 

4.  In  the  ocean  stream  in  a  palace  they  were  born. 

5.  Male  they  are  not:  female  they  are  not! 

6.  Wives  they  have  not!     Children  are  not  born  to  them! 

7.  Rules  they  have  not!     Government  they  know  not! 

8.  Prayers  they  hear  not! 

9.  There  are  seven!     There  are  seven!     Twice  over  there 


are  seven 


The  tablets  make  frequent   allusion  to   these  seven 
spirits.     One  starts  thus: 

1.  The  god  ( )  shall  stand  by  his  bedside: 

2.  These  seven  evil  spirits  he  shall  root  out  and  shall  expel 
them  from  his  body, 

3.  and  these  seven  shall  never  return  to  the  sick  man  again.17 

72 


SCIENCE  OF  BABYLONIA  AND  ASSYRIA 

Altogether  similar  are  the  exorcisms  intended  to 
ward  off  disease.  Professor  Sayce  has  published  trans- 
lations of  some  of  these.18  Each  of  these  ends  with 
the  same  phrase,  and  they  differ  only  in  regard  to  the 
particular  maladies  from  which  freedom  is  desired. 
One  reads: 

"From  wasting,  from  want  of  health,  from  the  evil  spirit 
of  the  ulcer,  from  the  spreading  quinsy  of  the  gullet,  from  the 
violent  ulcer,  from  the  noxious  ulcer,  may  the  king  of  heaven 
preserve,  may  the  king  of  earth  preserve." 

Another  is  phrased  thus: 

"From  the  cruel  spirit  of  the  head,  from  the  strong  spirit 
of  the  head,  from  the  head  spirit  that  departs  not,  from  the 
head  spirit  that  comes  not  forth,  from  the  head  spirit  that  will 
not  go,  from  the  noxious  head  spirit,  may  the  king  of  heaven 
preserve,  may  the  king  of  earth  preserve." 

As  to  omens  having  to  do  with  the  affairs  of  every- 
day life  the  number  is  legion.  For  example,  Moppert 
has  published,  in  the  Journal  Asiatique,19  the  transla- 
tion of  a  tablet  which  contains  on  its  two  sides  several 
scores  of  birth-portents,  a  few  of  which  may  be  quoted 
at  random : 

"When  a  woman  bears  a  child  and  it  has  the  ears  of  a  lion, 
a  strong  king  is  in  the  country."  "When  a  woman  bears  a 
child  and  it  has  a  bird's  beak,  that  country  is  oppressed." 
"When  a  woman  bears  a  child  and  its  right  hand  is  wanting, 
that  country  goes  to  destruction."  "  When  a  woman  bears  a 
child  and  its  feet  are  wanting,  the  roads  of  the  country  are 
cut;  that  house  is  destroyed."  "When  a  woman  bears  a 
child  and  at  the  time  of  its  birth  its  beard  is  grown,  floods 
are  in  the  country."  "When  a  woman  bears  a  child  and  at 
the  time  of  its  birth  its  mouth  is  open  and  speaks,  there  is 

73 


A   HISTORY   OF   SCIENCE 

pestilence  in  the  country,  the  Air-god  inundates  the  crops  of 
the  country,  injury  in  the  country  is  caused." 

Some  of  these  portents,  it  will  be  observed,  are  not 
in  much  danger  of  realization,  and  it  is  curious  to  sur- 
mise by  what  stretch  of  the  imagination  they  can  have 
been  invented.  There  is,  for  example,  on  the  same  tab- 
let just  quoted,  one  reference  which  assures  us  that 
"when  a  sheep  bears  a  lion  the  forces  march  multitu- 
dinously;  the  king  has  not  a  rival."  There  are  other 
omens,  however,  that  are  so  easy  of  realization  as  to 
lead  one  to  suppose  that  any  Babylonian  who  re- 
garded all  the  superstitious  signs  must  have  been  in 
constant  terror.  Thus  a  tablet  translated  by  Professor 
Sayce 20  gives  a  long  list  of  omens  furnished  by  dogs,  in 
which  we  are  assured  that: 

i.  If  a  yellow  dog  enters  into  the  palace,  exit  from  that 
palace  will  be  baleful. 

2.  If  a  dog  to  the  palace  goes,  and  on  a  throne  lies  down, 
that  palace  is  burned. 

3.  If  a  black  dog  into  a  temple  enters,  the  foundation  of  that 
temple  is  not  stable. 

4.  If  female  dogs  one  litter  bear,  destruction  to  the  city. 

It  is  needless  to  continue  these  citations,  since  they 
but  reiterate  endlessly  the  same  story.  It  is  interest- 
ing to  recall,  however,  that  the  observations  of  ani- 
mate nature,  which  were  doubtless  superstitious  'in 
their  motive,  had  given  the  Babylonians  some  ink- 
lings of  a  knowledge  of  classification.  Thus,  accord- 
ing to  Menant,21  some  of  the  tablets  from  Nineveh, 
which  are  written,  as  usual,  in  both  the  Sumerian  and 
Assyrian  languages,  and  which,  therefore,  like  prac- 

74 


SCIENCE  OF  BABYLONIA  AND  ASSYRIA 

tically  all  Assyrian  books,  draw  upon  the  knowledge 
of  old  Babylonia,  give  lists  of  animals,  making  an  at- 
tempt at  classification.  The  dog,  lion,  and  wolf  are 
placed  in  one  category;  the  ox,  sheep,  and  goat  in 
another;  the  dog  family  itself  is  divided  into  various 
races,  as  the  domestic  dog,  the  coursing  dog,  the  small 
dog,  the  dog  of  Elan,  etc.  Similar  attempts  at  classi- 
fication of  birds  are  found.  Thus,  birds  of  rapid  flight, 
sea-birds,  and  marsh-birds  are  differentiated.  Insects 
are  classified  according  to  habit;  those  that  attack 
plants,  animals,  clothing,  or  wood.  Vegetables  seem 
to  be  classified  according  to  their  usefulness.  One 
tablet  enumerates  the  uses  of  wood  according  to  its 
adaptability  for  timber-work  of  palaces,  or  construc- 
tion of  vessels,  the  making  of  implements  of  husbandry, 
or  even  furniture.  Minerals  occupy  a  long  series  in  these 
tablets.  They  are  classed  according  to  their  qualities, 
gold  and  silver  occupying  a  division  apart;  precious 
stones  forming  another  series.  Our  Babylonians,  then, 
must  be  credited  with  the  development  of  a  rudimen- 
tary science  of  natural  history. 

BABYLONIAN    MEDICINE 

We  have  just  seen  that  medical  practice  in  the 
Babylonian  world  was  strangely  under  the  cloud  of 
superstition.  But  it  should  be  understood  that  our 
estimate,  through  lack  of  correct  data,  probably  does 
much  less  than  justice  to  the  attainments  of  the 
physician  of  the  time.  As  already  noted,  the  existing 
tablets  chance  not  to  throw  much  light  on  the  subject. 
It  is  known,  however,  that  the  practitioner  of  medicine 
occupied  a  position  of  some  authority  and  responsibility. 

75 


A   HISTORY    OF   SCIENCE 

The  proof  of  this  is  found  in  the  clauses  relating  to 
the  legal  status  of  the  physician  which  are  contained 
in  the  now  famous  code22  of  the  Babylonian  King 
Khamurabi,  who  reigned  about  2300  years  before  our 
era.  These  clauses,  though  throwing  no  light  on  the 
scientific  attainments  of  the  physician  of  the  period, 
are  too  curious  to  be  omitted.  They  are  clauses  215 
to  227  of  the  celebrated  code,  and  are  as  follows: 

215.  If  a  doctor  has  treated  a  man  for  a  severe  wound  with 
a  lancet  of  bronze  and  has  cured  the  man,  or  has  opened  a 
tumor  with  a  bronze  lancet  and  has  cured  the  man's  eye, 
he  shall  receive  ten  shekels  of  silver. 

216.  If  it  was  a  freedman,  he  shall  receive  five  shekels  of 
silver. 

217.  If  it  was  a  man's  slave,  the  owner  of  the  slave  shall 
give  the  doctor  two  shekels  of  silver. 

218.  If  a  physician  has  treated  a  free-born  man  for  a 
severe  wound  with  a  lancet  of  bronze  and  has  caused  the  man 
to  die,  or  has  opened  a  tumor  of  the  man  with  a  lancet  of 
bronze  and  has  destroyed  his  eye,  his  hands  one  shall  cut 
off. 

219.  If  the  doctor  has  treated  the  slave  of  a  freedman  for  a 
severe  wound  with  a  bronze  lancet  and  has  caused  him  to  die, 
he  shall  give  back  slave  for  slave. 

220.  If  he  has  opened  his  tumor  with  a  bronze  lancet  and 
has  ruined  his  eye,  he  shall  pay  the  half  of  his  price  in  money. 

221.  If  a  doctor  has  cured  the  broken  limb  of  a  man,  or 
has  healed  his  sick  body,  the  patient  shall  pay  the  doctor 
five  shekels  of  silver. 

222.  If  it  was  a  freedman,  he  shall  give  three  shekels  of 
silver. 

223.  If  it  was  a  man's  slave,  the  owner  of  the  slave  shall 
give  two  shekels  of  silver  to  the  doctor. 

224.  If  the  doctor  of  oxen  and  asses  has  treated  an  ox 
or  an  ass  for  a  grave  wound  and  has  cured  it,  the  owner  of  the 
ox  or  the  ass  shall  give  to  the  doctor  as  his  pay  one-sixth 
of  a  shekel  of  silver. 

225.  If  he  has  treated  an  ox  or  an  ass  for  a  severe  wound 

76 


SCIENCE   OF  BABYLONIA  AND  ASSYRIA 

and  has  caused  its  death,  he  shall  pay  one-fourth  of  its  price 
to  the  owner  of  the  ox  or  the  ass. 

226.  If  a  barber-surgeon,  without  consent  of  the  owner 
of  a  slave,  has  branded  the  slave  with  an  indelible  mark,  one 
shall  cut  off  the  hands  of  that  barber. 

227.  If  any  one  deceive  the  surgeon-barber  and  make  him 
brand  a  slave  with  an  indelible  mark,  one  shall  kill  that  man 
and  bury  him  in  his  house.  The  barber  shall  swear,  "I  did 
not  mark  him  wittingly,"  and  he  shall  be  guiltless. 

ESTIMATES    OF    BABYLONIAN   SCIENCE 

Before  turning  from  the  Oriental  world  it  is  perhaps 
worth  while  to  attempt  to  estimate  somewhat  specifi- 
cally the  world  -  influence  of  the  name,  Babylonian 
science.  Perhaps  we  cannot  better  gain  an  idea  as  to 
the  estimate  put  upon  that  science  by  the  classical  world 
than  through  a  somewhat  extended  quotation  from  a 
classical  author.  Diodorus  Siculus,  who,  as  already 
noted,  lived  at  about  the  time  of  Augustus,  and  who, 
therefore,  scanned  in  perspective  the  entire  sweep  of 
classical  Greek  history,  has  left  us  a  striking  summary 
which  is  doubly  valuable  because  of  its  comparisons  of 
Babylonian  with  Greek  influence.  Having  viewed  the 
science  of  Babylonia  in  the  light  of  the  interpretations 
made  possible  by  the  recent  study  of  original  docu- 
ments, we  are  prepared  to  draw  our  own  conclusions 
from  the  statements  of  the  Greek  historian.  Here  is 
his  estimate  in  the  words  of  the  quaint  translation 
made  by  Philemon  Holland  in  the  year  1 700 : 23 

"They  being  the  most  ancient  Babylonians,  hold  the 
same  station  and  dignity  in  the  Common-wealth  as  the 
Egyptian  Priests  do  in  Egypt:  For  being  deputed  to 
Divine  Offices,  they  spend  all  their  Time  in  the  study 

77 


A    HISTORY   OF   SCIENCE 

of  Philosophy,  and  are  especially  famous  for  the  Art  of 
Astrology.  They  are  mightily  given  to  Divination, 
and  foretel  future  Events,  and  imploy  themselves  either 
by  Purifications,  Sacrifices,  or  other  Inchantments  to 
avert  Evils,  or  procure  good  Fortune  and  Success. 
They  are  skilful  likewise  in  the  Art  of  Divination,  by 
the  flying  of  Birds,  and  interpreting  of  Dreams  and 
Prodigies :  And  are  reputed  as  true  Oracles  (in  declar- 
ing what  will  come  to  pass)  by  their  exact  and  diligent 
viewing  the  Intrals  of  the  Sacrifices.  But  they  attain 
not  to  this  Knowledge  in  the  same  manner  as  the  Gre- 
cians do ;  for  the  Chaldeans  learn  it  by  Tradition  from 
their  Ancestors,  the  Son  from  the  Father,  who  are  all 
in  the  mean  time  free  from  all  other  publick  Offices  and 
Attendances;  and  because  their  Parents  are  their  Tu- 
tors, they  both  learn  every  thing  without  Envy,  and 
rely  with  more  confidence  upon  the  truth  of  what  is 
taught  them;  and  being  train'd  up  in  this  Learning 
from  their  very  Childhood,  they  become  most  famous 
Philosophers,  (that  Age  being  most  capable*  of  Learn- 
ing, wherein  they  spend  much  of  their  time).  But 
the  Grecians  for  the  most  part  come  raw  to  this  study, 
unfitted  and  unprepar'd,  and  are  long  before  they  at- 
tain to  the  Knowledge  of  this  Philosophy:  And  after 
they  have  spent  some  small  time  in  this  Study,  they  are 
many  times  call'd  off;  and  forc'd  to  leave  it,  in  order  to 
get  a  Livelihood  and  Subsistence.  And  although  some 
few  do  industriously  apply  themselves  to  Philosophy, 
yet  for  the  sake  of  Gain,  these  very  Men  are  opiniona- 
tive,  and  ever  and  anon  starting  new  and  high  Points, 
and  never  fix  in  the  steps  of  their  Ancestors.  But  the 
Barbarians  keeping  constantly  close  to  the  same  thing, 

78 


SCIENCE  OF   BABYLONIA  AND  ASSYRIA 

attain  to  a  perfect  and  distinct  Knowledge  in  every 
particular. 

"But  the  Grecians,  cunningly  catching  at  all  Op- 
portunities of  Gain,  make  new  Sects  and  Parties,  and 
by  their  contrary  Opinions  wrangling  and  quarelling 
concerning  the  chiefest  Points,  lead  their  Scholars  into 
a  Maze;  and  being  uncertain  and  doubtful  what  to 
pitch  upon  for  certain  truth,  their  Minds  are  fluctuat- 
ing and  in  suspence  all  the  days  of  their  Lives,  and  un- 
able to  give  a  certain  assent  unto  any  thing.  For  if 
any  Man  will  but  examine  the  most  eminent  Sects  of 
the  Philosophers,  he  shall  find  them  much  differing 
among  themselves,  and  even  opposing  one  another  in 
the  most  weighty  parts  of  their  Philosophy.  But  to 
return  to  the  Chaldeans,  they  hold  that  the  World  is 
eternal,  which  had  neither  any  certain  Beginning,  nor 
shall  have  any  End;  but  all  agree,  that  all  things  are 
order'd,  and  this  beautiful  Fabrick  is  supported  by  a 
Divine  Providence,  and  that  the  Motions  of  the  Heav- 
ens are  not  perform'd  by  chance  and  of  their  own  ac- 
cord, but  by  a  certain  and  determinate  Will  and  Ap- 
pointment of  the  Gods. 

"  Therefore  from  a  long  observation  of  the  Stars,  and 
an  exact  Knowledge  of  the  motions  and  influences  of 
every  one  of  them,  wherein  they  excel  all  others,  they 
fortel  many  things  that  are  to  come  to  pass. 

"  They  say  that  the  Five  Stars  which  some  call  Plan- 
ets, but  they  Interpreters,  are  most  worthy  of  Consid- 
eration, both  for  their  motions  and  their  remarkable  in- 
fluences, especially  that  which  the  Grecians  call  Saturn. 
The  brightest  of  them  all,  and  which  often  portends 
many  and  great  Events,  they  call  Sol,  the  other  Four 

79 


A   HISTORY   OF   SCIENCE 

they  name  Mars,  Venus,  Mercury,  and  Jupiter,  with 
our  own  Country  Astrologers.  They  give  the  Name  of 
Interpreters  to  these  Stars,  because  these  only  by  a 
peculiar  Motion  do  portend  things  to  come,  and  instead 
of  Jupiters,  do  declare  to  Men  before-hand  the  good- 
will of  the  Gods;  whereas  the  other  Stars  (not  being  of 
the  number  of  the  Planets)  have  a  constant  ordinary 
motion.  Future  Events  (they  say)  are  pointed  at 
sometimes  by  their  Rising,  and  sometimes  by  their 
Setting,  and  at  other  times  by  their  Colour,  as  may  be 
experienc'd  by  those  that  will  diligently  observe  it; 
sometimes  foreshewing  Hurricanes,  at  other  times 
Tempestuous  Rains,  and  then  again  exceeding 
Droughts.  By  these,  they  say,  are  often  portended 
the  appearance  of  Comets,  Eclipses  of  the  Sun  and 
Moon,  Earthquakes  and  all  other  the  various  Changes 
and  remarkable  effects  in  the  Air,  boding  good  and  bad, 
not  only  to  Nations  in  general,  but  to  Kings  and  Pri- 
vate Persons  in  particular.  Under  the  course  of  these 
Planets,  they  say  are  Thirty  Stars,  which  they  call 
Counselling  Gods,  half  of  whom  observe  what  is  done 
under  the  Earth,  and  the  other  half  take  notice  of  the 
actions  of  Men  upon  the  Earth,  and  what  is  transacted 
in  the  Heavens.  Once  every  Ten  Days  space  (they  say) 
one  of  the  highest  Order  of  these  Stars  descends  to 
them  that  are  of  the  lowest,  like  a  Messenger  sent  from 
them  above;  and  then  again  another  ascends  from 
those  below  to  them  above,  and  that  this  is  their  con- 
stant natural  motion  to  continue  for  ever.  The  chief 
of  these  Gods,  they  say,  are  Twelve  in  number,  to  each 
of  which  they  attribute  a  Month,  and  one  Sign  of  the 
Twelve  in  the  Zodiack. 

80 


SCIENCE  OF  BABYLONIA  AND  ASSYRIA 

"Through  these  Twelve  Signs  the  Sun,  Moon,  and 
the  other  Five  Planets  run  their  Course.  The  Sun  in  a 
Years  time,  and  the  Moon  in  the  space  of  a  Month. 
To  every  one  of  the  Planets  they  assign  their  own  prop- 
er Courses,  which  are  perform'd  variously  in  lesser  or 
shorter  time  according  as  their  several  motions  are 
quicker  or  slower.  These  Stars,  they  say,  have  a 
great  influence  both  as  to  good  and  bad  in  Mens  Na- 
tivities; and  from  the  consideration  of  their  several 
Natures,  may  be  foreknown  what  will  befal  Men  after- 
wards. As  they  foretold  things  to  come  to  other 
Kings  formerly,  so  they  did  to  Alexander  who  con- 
quer'd  Darius,  and  to  his  Successors  Antigonus  and 
Seleucus  Nicator;  and  accordingly  things  fell  out  as 
they  declar'd;  which  we  shall  relate  particularly  here- 
after in  a  more  convenient  time.  They  tell  likewise 
private  Men  their  Fortunes  so  certainly,  that  those  who 
have  found  the  thing  true  by  Experience,  have  esteem'd 
it  a  Miracle,  and  above  the  reach  of  man  to  perform. 
Out  of  the  Circle  of  the  Zodiack  they  describe  Four  and 
Twenty  Stars,  Twelve  towards  the  North  Pole,  and  as 
many  to  the  South. 

"Those  which  we  see,  they  assign  to  the  living;  and 
the  other  that  do  not  appear,  they  conceive  are  Con- 
stellations for  the  Dead;  and  they  term  them  Judges 
of  all  things.  The  Moon,  they  say,  is  in  the  lowest 
Orb;  and  being  therefore  next  to  the  Earth  (because 
she  is  so  small),  she  finishes  her  Course  in  a  little 
time,  not  through  the  swiftness  of  her  Motion,  but 
the  shortness  of  her  Sphear.  In  that  which  they 
affirm  (that  she  has  but  a  borrow'd  light,  and  that 
when  she  is  eclips'd,  it's  caus'd  by  the  interposition 
6  81 


A   HISTORY   OF   SCIENCE 

of  the  shadow  of  the  Earth)  they  agree   with   the 
Grecians. 

"Their  Rules  and  Notions  concerning  the  Eclipses  of 
the  Sun  are  but  weak  and  mean,  which  they  dare  not 
positively  foretel,  nor  fix  a  certain  time  for  them. 
They  have  likewise  Opinions  concerning  the  Earth 
peculiar  to  themselves,  affirming  it  to  resemble  a  Boat, 
and  to  be  hollow,  to  prove  which,  and  other  things  re- 
lating to  the  frame  of  the  World,  they  abound  in  Argu- 
ments ;  but  to  give  a  particular  Account  of  'em,  we  con- 
ceive would  be  a  thing  foreign  to  our  History.  But 
this  any  Man  may  justly  and  truly  say,  That  the  Chal- 
deans far  exceed  all  other  Men  in  the  Knowledge  of 
Astrology,  and  have  study'd  it  most  of  any  other  Art 
or  Science:  But  the  number  of  years  during  which  the 
Chaldeans  say,  those  of  their  Prof  essionhave  given  them- 
selves to  the  study  of  this  natural  Philosophy,  is  incred- 
ible ;  for  when  Alexander  was  in  Asia,  they  reckon'd  up 
Four  Hundred  and  Seventy  Thousand  Years  since  they 
first  began  to  observe  the  Motions  of  the  Stars." 

Let  us  now  supplement  this  estimate  of  Babylonian 
influence  with  another  estimate  written  in  our  own 
day,  and  quoted  by  one  of  the  most  recent  historians 
of  Babylonia  and  Assyria.24  The  estimate  in  question 
is  that  of  Canon  Rawlinson  in  his  Great  Oriental  Mon- 
archies,25    Of  Babylonia  he  says: 

"  Hers  was  apparently  the  genius  which  excogitated 
an  alphabet ;  worked  out  the  simpler  problems  of  arith- 
metic; invented  implements  for  measuring  the  lapse 
of  time ;  conceived  the  idea  of  raising  enormous  struct- 

82 


SCIENCE  OF  BABYLONIA  AND  ASSYRIA 

tires  with  the  poorest  of  all  materials,  clay ;  discovered 
the  art  of  polishing,  boring,  and  engraving  gems;  re- 
produced with  truthfulness  the  outlines  of  human  and 
animal  forms;  attained  to  high  perfection  in  textile 
fabrics;  studied  with  success  the  motions  of  the  heav- 
enly bodies;  conceived  of  grammar  as  a  science;  elab- 
orated a  system  of  law;  saw  the  value  of  an  exact 
chronology — in  almost  every  branch  of  science  made  a 
beginning,  thus  rendering  it  comparatively  easy  for 
other  nations  to  proceed  with  the  superstructure.  .  .  . 
It  was  from  the  East,  not  from  Egypt,  that  Greece  de- 
rived her  architecture,  her  sculpture,  her  science,  her 
philosophy,  her  mathematical  knowledge — in  a  word, 
her  intellectual  life.  And  Babylon  was  the  source  to 
which  the  entire  stream  of  Eastern  civilization  may 
be  traced.  It  is  scarcely  too  much  to  say  that,  but 
for  Babylon,  real  civilization  might  not  yet  have 
dawned  upon  the  earth." 

Considering  that  a  period  of  almost  two  thousand 
years  separates  the  times  of  writing  of  these  two  esti- 
mates, the  estimates  themselves  are  singularly  in  uni- 
son. They  show  that  the  greatest  of  Oriental  nations 
has  not  suffered  in  reputation  at  the  hands  of  posterity. 
It  is  indeed  almost  impossible  to  contemplate  the  monu- 
ments of  Babylonian  and  Assyrian  civilization  that  are 
now  preserved  in  the  European  and  American  museums 
without  becoming  enthusiastic.  That  certainly  was 
a  wonderful  civilization  which  has  left  us  the  tablets  on 
which  are  inscribed  the  laws  of  a  Khamurabi  on  the 
one  hand,  and  the  art  treasures  of  the  palace  of  an 
Asshurbanipal  on  the  other.     Yet  a  candid  considera- 

83 


A   HISTORY   OF  SCIENCE 

tion  of  the  scientific  attainments  of  the  Babylonians 
and  Assyrians  can  scarcely  arouse  us  to  a  like  enthu- 
siasm. In  considering  the  subject  we  have  seen  that, 
so  far  as  pure  science  is  concerned,  the  efforts  of  the 
Babylonians  and  Assyrians  chiefly  centred  about  the 
subjects  of  astrology  and  magic.  With  the  records 
of  their  ghost-haunted  science  fresh  in  mind,  one  might 
be  forgiven  for  a  momentary  desire  to  take  issue  with 
Canon  Rawlinson's  words.  We  are  assured  that  the 
scientific  attainments  of  Europe  are  almost  solely  to  be 
credited  to  Babylonia  and  not  to  Egypt,  but  we  should 
not  forget  that  Plato,  the  greatest  of  the  Greek  think- 
ers, went  to  Egypt  and  not  to  Babylonia  to  pursue  his 
studies  when  he  wished  to  penetrate  the  secrets  of 
Oriental  science  and  philosophy.  Clearly,  then,  clas- 
sical Greece  did  not  consider  Babylonia  as  having  a 
monopoly  of  scientific  knowledge,  and  we  of  to-day, 
when  we  attempt  to  weigh  the  new  evidence  that  has 
come  to  us  in  recent  generations  with  the  Babylonian 
records  themselves,  find  that  some,  at  least,  of  the 
heritages  for  which  Babylonia  has  been  praised  are  of 
more  than  doubtful  value.  Babylonia,  for  example, 
gave  us  our  seven-day  week  and  our  system  of  com- 
puting by  twelves.  But  surely  the  world  could  have 
got  on  as  well  without  that  magic  number  seven;  and 
after  some  hundreds  of  generations  we  are  coming  to 
feel  that  the  decimal  system  of  the  Egyptians  has  ad- 
vantages over  the  duodecimal  system  of  the  Baby- 
lonians. Again,  the  Babylonians  did  not  invent  the 
alphabet ;  they  did  not  even  accept  it  when  all  the  rest 
of  the  world  had  recognized  its  value.  In  grammar 
and  arithmetic,  as  with  astronomy,  they  seemed  not  to 

84 


SCIENCE  OF  BABYLONIA  AND  ASSYRIA 

have  advanced  greatly,  if  at  all,  upon  the  Egyptians. 
One  field  in  which  they  stand  out  in  startling  pre- 
eminence is  the  field  of  astrology ;  but  this,  in  the  esti- 
mate of  modern  thought,  is  the  very  negation  of 
science.  Babylonia  impressed  her  superstitions  on 
the  Western  world,  and  when  we  consider  the  baleful 
influence  of  these  superstitions,  we  may  almost  ques- 
tion whether  we  might  not  reverse  Canon  Rawlinson's 
estimate  and  say  that  perhaps  but  for  Babylonia  real 
civilization,  based  on  the  application  of  true  science, 
might  have  dawned  upon  the  earth  a  score  of  centuries 
before  it  did.  Yet,  after  all,  perhaps  this  estimate  is 
unjust.  Society,  like  an  individual  organism,  must 
creep  before  it  can  walk,  and  perhaps  the  Babylonian 
experiments  in  astrology  and  magic,  which  European 
civilization  was  destined  to  copy  for  some  three  or 
four  thousand  years,  must  have  been  made  a  part  of 
the  necessary  evolution  of  our  race  in  one  place  or  in 
another.  That  thought,  however,  need  not  blind  us 
to  the  essential  fact,  which  the  historian  of  science 
must  needs  admit,  that  for  the  Babylonian,  despite  his 
boasted  culture,  science  spelled  superstition. 


IV 
THE  DEVELOPMENT  OF  THE  ALPHABET 

BEFORE  we  turn  specifically  to  the  new  world  of 
the  west,  it  remains  to  take  note  of  what  may 
perhaps  be  regarded  as  the  very  greatest  achievement 
of  ancient  science.  This  was  the  analysis  of  speech 
sounds,  and  the  resulting  development  of  a  system  of 
alphabetical  writing.  To  comprehend  the  series  of 
scientific  inductions  which  led  to  this  result,  we  must 
go  back  in  imagination  and  ■  trace  briefly  the  develop- 
ment of  the  methods  of  recording  thought  by  means  of 
graphic  symbols.  In  other  words,  we  must  trace 
the  evolution  of  the  art  of  writing.  In  doing  so  we 
cannot  hold  to  national  lines  as  we  have  done  in  the 
preceding  two  chapters,  though  the  efforts  of  the  two 
great  scientific  nations  just  considered  will  enter 
prominently  into  the  story. 

The  familiar  Greek  legend  assures  us  that  a  Phoeni- 
cian named  Kadmus  was  the  first  to  bring  a  knowledge 
of  letters  into  Europe.  An  elaboration  of  the  story, 
current  throughout  classical  times,  offered  the  further 
explanation  that  the  Phoenicians  had  in  turn  ac- 
quired the  art  of  writing  from  the  Egyptians  or 
Babylonians.  Knowledge  as  to  the  true  origin  and 
development  of  the  art  of  writing  did  not  extend  in 
antiquity  beyond  such  vagaries  as  these.  Nine- 
teenth-century studies  gave  the  first  real  clews  to  an 

86 


THE    MOABITE    STONE 

(With  one  possible  exception  the  oldest  known  example  of  the  Phoenician  writing, 
shows  an  inscription  of  Mesha,  king  of  Moab,  and  dates  from  early  in  the 
ninth  century,  B.C.) 


DEVELOPMENT  OF  THE  ALPHABET 

understanding  of  the  subject.  These  studies  tended 
to  authenticate  the  essential  fact  on  which  the  legend 
of  Kadmus  was  founded;  to  the  extent,  at  least,  of 
making  it  probable  that  the  later  Grecian  alphabet 
was  introduced  from  Phoenicia — though  not,  of  course, 
by  any  individual  named  Kadmus,  the  latter  being, 
indeed,  a  name  of  purely  Greek  origin.  Further  studies 
of  the  past  generation  tended  to  corroborate  the 
ancient  belief  as  to  the  original  source  of  the  Phoenician 
alphabet,  but  divided  scholars  between  two  opinions: 
the  one  contending  that  the  Egyptian  hieroglyphics 
were  the  source  upon  which  the  Phoenicians  drew ;  and 
the  other  contending  with  equal  fervor  that  the  Baby- 
lonian wedge  character  must  be  conceded  that  honor. 

But,  as  has  often  happened  in  other  fields  after 
years  of  acrimonious  controversy,  a  new  discovery 
or  two  may  suffice  to  show  that  neither  contestant 
was  right.  After  the  Egyptologists  of  the  school  of 
De  Rouge1  thought  they  had  demonstrated  that  the 
familiar  symbols  of  the  Phoenician  alphabet  had  been 
copied  from  that  modified  form  of  Egyptian  hiero- 
glyphics known  as  the  hieratic  writing,  the  Assyriolo- 
gists  came  forward  to  prove  that  certain  characters  of 
the  Babylonian  syllabary  also  show  a  likeness  to  the 
alphabetical  characters  that  seemingly  could  not  be 
due  to  chance.  And  then,  when  a  settlement  of  the 
dispute  seemed  almost  hopeless,  it  was  shown  through 
the  Egyptian  excavations  that  characters  even  more 
closely  resembling  those  in  dispute  had  been  in  use 
all  about  the  shores  of  the  Mediterranean,  quite  in- 
dependently of  either  Egyptian  or  Assyrian  writings, 
from  periods  so  ancient  as  to  be  virtually  prehistoric. 

87 


A   HISTORY   OF   SCIENCE 

Coupled  with  this  disconcerting  discovery  are  the 
revelations  brought  to  light  by  the  excavations  at  the 
sites  of  Knossos  and  other  long-buried  cities  of  the 
island  of  Crete.2  These  excavations,  which  are  still  in 
progress,  show  that  the  art  of  writing  was  known  and 
practised  independently  in  Crete  before  that  cataclys- 
mic overthrow  of  the  early  Greek  civilization  which 
archaeologists  are  accustomed  to  ascribe  to  the  hypo- 
thetical invasion  of  the  Dorians.  The  significance  of 
this  is  that  the  art  of  writing  was  known  in  Europe 
long  before  the  advent  of  the  mythical  Kadmus.  But 
since  the  early  Cretan  scripts  are  not  to  be  identified 
with  the  scripts  used  in  Greece  in  historical  times, 
whereas  the  latter  are  undoubtedly  of  lineal  descent 
from  the  Phoenician  alphabet,  the  validity  of  the 
Kadmus  legend,  in  a  modified  form,  must  still  be 
admitted. 

As  has  just  been  suggested,  the  new  knowledge, 
particularly  that  which  related  to  the  great  antiquity 
of  characters  similar  to  the  Phoenician  alphabetical 
signs,  is  somewhat  disconcerting.  Its  general  trend, 
however,  is  quite  in  the  same  direction  with  most  of  the 
new  archaeological  knowledge  of  recent  decades — that 
is  to  say,  it  tends  to  emphasize  the  idea  that  human 
civilization  in  most  of  its  important  elaborations  is 
vastly  older  than  has  hitherto  been  supposed.  It 
may  be  added,  however,  that  no  definite  clews  are  as 
yet  available  that  enable  us  to  fix  even  an  approxi- 
mate date  for  the  origin  of  the  Phoenician  alphabet. 
The  signs,  to  which  reference  has  been  made,  may 
well  have  been  in  existence  for  thousands  of  years, 
utilized  merely  as  property  marks,  symbols  for  count- 

88 


p  ■ 

3 

S'  o 

S  2. 

,1  TO 


***^ 


DEVELOPMENT  OF  THE  ALPHABET 

ing  and  the  like,  before  the  idea  of  setting  them  aside  as 
phonetic  symbols  was  ever  conceived.  Nothing  is 
more  certain,  in  the  judgment  of  the  present-day  in- 
vestigator, than  that  man  learned  to  write  by  slow  and 
painful  stages.  It  is  probable  that  the  conception 
of  such  an  analysis  of  speech  sounds  as  would  make 
the  idea  of  an  alphabet  possible  came  at  a  very  late 
stage  of  social  evolution,  and  as  the  culminating 
achievement  of  a  long  series  of  improvements  in  the 
art  of  writing.  The  precise  steps  that  marked  this 
path  of  intellectual  development  can  for  the  most 
part  be  known  only  by  inference;  yet  it  is  probable 
that  the  main  chapters  of  the  story  may  be  repro- 
duced with  essential  accuracy. 

FIRST   STEPS 

For  the  very  first  chapters  of  the  story  we  must  go 
back  in  imagination  to  the  prehistoric  period.  Even 
barbaric  man  feels  the  need  of  self-expression,  and 
strives  to  make  his  ideas  manifest  to  other  men  by 
pictorial  signs.  The  cave-dwellers  scratched  pictures 
of  men  and  animals  on  the  surface  of  a  reindeer  horn 
or  mammoth  tusk  as  mementos  of  his  prowess.  The 
American  Indian  does  essentially  the  same  thing  to-day, 
making  pictures  that  crudely  record  his  successes  in 
war  and  the  chase.  The  Northern  Indian  had  got  no 
farther  than  this  when  the  white  man  discovered 
America;  but  the  Aztecs  of  the  Southwest  and  the 
Maya  people  of  Yucatan  had  carried  their  picture- 
making  to  a  much  higher  state  of  elaboration.3  They 
had  developed  systems  of  pictographs  or  hieroglyphics 

89 


A   HISTORY   OF   SCIENCE 

that  would  doubtless  in  the  course  of  generations  have 
been  elaborated  into  alphabetical  systems,  had  not  the 
Europeans  cut  off  the  civilization  of  which  they  were 
the  highest  exponents. 

What  the  Aztec  and  Maya  were  striving  towards  in 
the  sixteenth  century  a.d.,  various  Oriental  nations 
had  attained  at  least  five  or  six  thousand  years  earlier. 
In  Egypt  at  the  time  of  the  pyramid-builders,  and  in 
Babylonia  at  the  same  epoch,  the  people  had  developed 
systems  of  writing  that  enabled  them  not  merely  to 
present  a  limited  range  of  ideas  pictorially,  but  to 
express  in  full  elaboration  and  with  finer  shades  of 
meaning  all  the  ideas  that  pertain  to  highly  cultured 
existence.  The  man  of  that  time  made  records  of 
military  achievements,  recorded  the  transactions  of 
every-day  business  life,  and  gave  expression  to  his 
moral  and  spiritual,  aspirations  in  a  way  strangely  com- 
parable to  the  manner  of  our  own  time.  He  had 
perfected  highly  elaborate  systems  of  writing. 

EGYPTIAN    WRITING 

Of  the  two  ancient  systems  of  writing  just  referred 
to  as  being  in  vogue  at  the  so-called  dawnings  of 
history,  the  more  picturesque  and  suggestive  was  the 
hieroglyphic  system  of  the  Egyptians.  This  is  a 
curiously  conglomerate  system  of  writing,  made  up 
in  part  of  symbols  reminiscent  of  the  crudest  stages  of 
picture-writing,  in  part  of  symbols  having  the  phonetic 
value  of  syllables,  and  in  part  of  true  alphabetical 
letters.  In  a  word,  the  Egyptian  writing  represents  in 
itself  the  elements  of  the  various  stages  through  which 
the  art  of  writing  has  developed.4     We  must  conceive 

90 


e     > 


DEVELOPMENT  OF  THE  ALPHABET 

that  new  features  were  from  time  to  time  added  to  it, 
while  the  old  features,  curiously  enough,  were  not 
given  up. 

Here,  for  example,  in  the  midst  of  unintelligible  lines 
and  pot-hooks,  are  various  pictures  that  are  instantly 
recognizable  as  representations  of  hawks,  lions,  ibises, 
and  the  like.  It  can  hardly  be  questioned  that  when 
these  pictures  were  first  used  calligraphically  they 
were  meant  to  represent  the  idea  of  a  bird  or  animal. 
In  other  words,  the  first  stage  of  picture-writing  did 
not  go  beyond  the  mere  representation  of  an  eagle  by 
the  picture  of  an  eagle.  But  this,  obviously,  would 
confine  the  presentation  of  ideas  within  very  narrow 
limits.  In  due  course  some  inventive  genius  con- 
ceived the  thought  of  symbolizing  a  picture.  To 
him  the  outline  of  an  eagle  might  represent  not  merely 
an  actual  bird,  but  the  thought  of  strength,  of  courage, 
or  of  swift  progress.  Such  a  use  of  symbols  obviously 
extends  the  range  of  utility  of  a  nascent  art  of  writing. 
Then  in  due  course  some  wonderful  psychologist — or 
perhaps  the  joint  efforts  of  many  generations  of 
psychologists — made  the  astounding  discovery  that 
the  human  voice,  which  seems  to  flow  on  in  an  un- 
broken stream  of  endlessly  varied  modulations  and 
intonations,  may  really  be  analyzed  into  a  comparative- 
ly limited  number  of  component  sounds — into  a  few 
hundreds  of  syllables.  That  wonderful  idea  conceived, 
it  was  only  a  matter  of  time  until  it  would  occur  to 
some  other  enterprising  genius  that  by  selecting  an 
arbitrary  symbol  to  represent  each  one  of  these 
elementary  sounds  it  would  be  possible  to  make  a 
written  record  of  the  words  of  human  speech  which 

9i 


A   HISTORY   OF   SCIENCE 

could  be  reproduced — rephonated — by  some  one  who 
had  never  heard  the  words  and  did  not  know  in  ad- 
vance what  this  written  record  contained.  This,  of 
course,  is  what  every  child  learns  to  do  now  in  the 
primer  class,  but  we  may  feel  assured  that  such  an  idea 
never  occurred  to  any  human  being  until  the  peculiar 
forms  of  pictographic  writing  just  referred  to  had 
been  practised  for  many  centuries.  Yet,  as  we  have 
said,  some  genius  of  prehistoric  Egypt  conceived  the 
idea  and  put  it  into  practical  execution,  and  the 
hieroglyphic  writing  of  which  the  Egyptians  were  in 
full  possession  at  the  very  beginning  of  what  we  term 
the  historical  period  made  use  of  this  phonetic  system 
along  with  the  ideographic  system  already  described. 

So  fond  were  the  Egyptians  of  their  pictorial  sym- 
bols used  ideographically  that  they  clung  to  them 
persistently  throughout  the  entire  period  of  Egyptian 
history.  They  used  symbols  as  phonetic  equivalents 
very  frequently,  but  they  never  learned  to  depend 
upon  them  exclusively.  The  scribe  always  inter- 
spersed his  phonetic  signs  with  some  other  signs  in- 
tended as  graphic  aids.  After  spelling  a  word  out  in 
full,  he  added  a  picture,  sometimes  even  two  or  three 
pictures,  representative  of  the  individual  thing,  or  at 
least  of  the  type  of  thing  to  which  the  word  belongs. 
Two  or  three  illustrations  will  make  this  clear. 

Thus  qeften,  monkey,  is  spelled  out  in  full,  but  the 
picture  of  a  monkey  is  added  as  a  determinative ; 
second,  genu,  cavalry,  after  being  spelled,  is  made  un- 
equivocal by  the  introduction  of  a  picture  of  a  horse ; 
third,  temati,  wings,  though  spelled  elaborately,  has 
pictures  of  wings  added ;  and  fourth,  tatu,  quadrupeds, 

92 


DEVELOPMENT  OF  THE  ALPHABET 

after  being  spelled,  has  a  picture  of  a  quadruped,  and 
then  the  picture  of  a  hide,  which  is  the  usual  de- 
terminative of  a  quadruped,  followed  by  three  dashes 
to  indicate  the  plural  number. 

It  must  not  be  supposed,  however,  that  it  was  a  mere 
whim  which  led  the  Egyptians  to  the  use  of  this 
system  of  determinatives.  There  was  sound  reason 
back  of  it.  It  amounted  to  no  more  than  the  expe- 
dient we  adopt  when  we  spell  "to,"  "two,"  or  "too," 
in  indication  of  a  single  sound  with  three  different 
meanings.  The  Egyptian  language  abounds  in  words 
having  more  than  one  meaning,  and  in  writing  these 
it  is  obvious  that  some  means  of  distinction  is  desirable. 
The  same  thing  occurs  even  more  frequently  in  the 
Chinese  language,  which  is  monosyllabic.  The  Chinese 
adopt  a  more  clumsy  expedient,  supplying  a  different 
symbol  for  each  of  the  meanings  of  a  syllable;  so  that 
while  the  actual  word-sounds  of  their  speech  are  only 
a  few  hundreds  in  number,  the  characters  of  their 
written  language  mount  high  into  the  thousands. 

BABYLONIAN   WRITING 

While  the  civilization  of  the  Nile  Valley  was  develop- 
ing this  extraordinary  system  of  hieroglyphics,  the  in- 
habitants of  Babylonia  were  practising  the  art  of 
writing  along  somewhat  different  lines.  It  is  certain 
that  they  began  with  picture -making,  and  that  in  due 
course  they  advanced  to  the  development  of  the 
syllabary ;  but,  unlike  their  Egyptian  cousins,  the  men 
of  Babylonia  saw  fit  to  discard  the  old  system  when 
they  had  perfected  a  better  one.5  So  at  a  very  early 
day  their  writing-^s  revealed  to  us  now  through  the 

93 


A    HISTORY   OF   SCIENCE 

recent  excavations — had  ceased  to  have  that  pictorial 
aspect  which  distinguishes  the  Egyptian  script.  What 
had  originally  been  pictures  of  objects — fish,  houses, 
and  the  like  —  had  come  to  be  represented  by  mere 
aggregations  of  wedge-shaped  marks.  As  the  writing 
of  the  Babylonians  was  chiefly  inscribed  on  soft  clay, 
the  adaptation  of  this  wedge-shaped  mark  in  lieu  of 
an  ordinary  line  was  probably  a  mere  matter  of  con- 
venience, since  the  sharp-cornered  implement  used  in 
making  the  inscription  naturally  made  a  wedge-shaped 
impression  in  the  clay.  That,  however,  is  a  detail. 
The  essential  thing  is  that  the  Babylonian  had  so 
fully  analyzed  the  speech-sounds  that  he  felt  entire 
confidence  in  them,  and  having  selected  a  sufficient 
number  of  conventional  characters — each  made  up  of 
wedge  -  shaped  lines  —  to  represent  all  the  phonetic 
sounds  of  his  language,  spelled  the  words  out  in 
syllables  and  to  some  extent  dispensed  with  the 
determinative  signs  which,  as  we  have  seen,  played  so 
prominent  a  part  in  the  Egyptian  writing.  His 
cousins  the  Assyrians  used  habitually  a  system  of 
writing  the  foundation  of  which  was  an  elaborate 
phonetic  syllabary;  a  system,  therefore,  far  removed 
from  the  old  crude  pictograph,  and  in  some  respects 
much  more  developed  than  the  complicated  Egyptian 
method;  yet,  after  all,  a  system  that  stopped  short  of 
perfection  by  the  wide  gap  that  separates  the  syllabary 
from  the  true  alphabet. 

A  brief  analysis  of  speech  sounds  will  aid  us  in  un- 
derstanding the  real  nature  of  the  syllabary.  Let  us 
take  for  consideration  the  consonantal  sound  repre- 
sented by  the  letter  b.    A  moment's  consideration  will 

94 


DEVELOPMENT  OF  THE  ALPHABET 

make  it  clear  that  this  sound  enters  into  a  large 
number  of  syllables.  There  are,  for  example,  at  least 
twenty  vowel  sounds  in  the  English  language,  not  to 
speak  of  certain  digraphs;  that  is  to  say,  each  of  the 
important  vowels  has  from  two  to  six  sounds.  Each 
of  these  vowel  sounds  may  enter  into  combination 
with  the  b  sound  alone  to  form  three  syllables;  as 
ba,  ab,  bal,  be,  eb,  bel,  etc.  Thus  there  are  at  least 
sixty  fe-sound  syllables.  But  this  is  not  the  end,  for 
other  consonantal  sounds  may  be  associated  in  the 
syllables  in  such  combinations  as  bad,  bed,  bar,  bark, 
cab,  etc.  As  each  of  the  other  twenty  odd  con- 
sonantal sounds  may  enter  into  similar  combinations, 
it  is  obvious  that  there  are  several  hundreds  of  funda- 
mental syllables  to  be  taken  into  account  in  any 
syllabic  system  of  writing.  For  each  of  these  syl- 
lables a  symbol  must  be  set  aside  and  held  in  reserve 
as  the  representative  of  that  particular  sound.  A 
perfect  syllabary,  then,  would  require  some  hundred 
or  more  of  symbols  to  represent  b  sounds  alone;  and 
since  the  sounds  for  c,  d,  /,  and  the  rest  are  equally 
varied,  the  entire  syllabary  would  run  into  thousands 
of  characters,  almost  rivalling  in  complexity  the 
Chinese  system.  But  in  practice  the  most  perfect 
syllabary,  such  as  that  of  the  Babylonians,  fell  short  of 
this  degree  of  precision  through  ignoring  the  minor 
shades  of  sound ;  just  as  our  own  alphabet  is  content  to 
represent  some  thirty  vowel  sounds  by  five  letters, 
ignoring  the  fact  that  a,  for  example,  has  really  half  a 
dozen  distinct  phonetic  values.  By  such  slurring  of 
sounds  the  syllabary  is  reduced  far  below  its  ideal  limits ; 
yet  even  so  it  retains  three  or  four  hundred  characters. 

95 


A    HISTORY   OF   SCIENCE 

In  point  of  fact,  such  a  work  as  Professor  Delitzsch's 
Assyrian  Grammar 6  presents  signs  for  three  hundred 
and  thirty-four  syllables,  together  with  sundry  alterna- 
tive signs  and  determinatives  to  tax  the  memory  of 
the  would-be  reader  of  Assyrian.  Let  us  take  for 
example  a  few  of  the  b  sounds.  It  has  been  explained 
that  the  basis  of  the  Assyrian  written  character  is  a 
simple  wedge-shaped  or  arrow-head  mark.  Variously 
repeated  and  grouped,  these  marks  make  up  the  syl- 
labic characters. 

To  learn  some  four  hundred  such  signs  as  these 
was  the  task  set,  as  an  equivalent  of  learning  the 
a  b  c's,  to  any  primer  class  in  old  Assyria  in  the  long 
generations  when  that  land  was  the  culture  centre  of 
the  world.  Nor  was  the  task  confined  to  the  natives 
of  Babylonia  and  Assyria  alone.  About  the  fifteenth 
century  B.C.,  and  probably  for  a  long  time  before  and 
after  that  period,  the  exceedingly  complex  syllabary 
of  the  Babylonians  was  the  official  means  of  com- 
munication throughout  western  Asia  and  between  Asia 
and  Egypt,  as  we  know  from  the  chance  discovery 
of  a  collection  of  letters  belonging  to  the  Egyptian 
king  Khun-aten,  preserved  at  Tel-el- Amarna.  In  the 
time  of  Ramses  the  Great  the  Babylonian  writing  was 
in  all  probability  considered  by  a  majority  of  the 
most  highly  civilized  people  in  the  world  to  be  the 
most  perfect  script  practicable.  Doubtless  the  aver- 
age scribe  of  the  time  did  not  in  the  least  realize  the 
waste  of  energy  involved  in  his  labors,  or  ever  suspect 
that  there  could  be  any  better  way  of  writing. 

Yet  the  analysis  of  any  one  of  these  hundreds  of 
syllables  into  its  component  phonetic  elements — had 

96 


OLD    BABYLONIAN    INSCRIPTION. 

Date,  about  -j;oo  B.C. 

British  Museum,  London. 


(Reproduced  from  Williams'  History  of  the  Art  of  Writing.) 


DEVELOPMENT  OF  THE  ALPHABET 

any  one  been  genius  enough  to  make  such  analysis — 
would  have  given  the  key  to  simpler  and  better  things. 
But  such  an  analysis  was  very  hard  to  make,  as  the 
sequel  shows.  Nor  is  the  utility  of  such  an  analysis 
self-evident,  as  the  experience  of  the  Egyptians  proved. 
The  vowel  sound  is  so  intimately  linked  with  the  con- 
sonant—  the  con- sonant,  implying  this  intimate  re- 
lation in  its  very  name  —  that  it  seemed  extremely 
difficult  to  give  it  individual  recognition.  To  set  off 
the  mere  labial  beginning  of  the  sound  by  itself,  and  to 
recognize  it  as  an  all-essential  element  of  phonation, 
was  the  feat  at  which  human  intelligence  so  long 
balked.  The  germ  of  great  things  lay  in  that  analysis. 
It  was  a  process  of  simplification,  and  all  art  develop- 
ment is  from  the  complex  to  the  simple.  Unfort- 
unately, however,  it  did  not  seem  a  simplification,  but 
rather  quite  the  reverse.  We  may  well  suppose  that 
the  idea  of  wresting  from  the  syllabary  its  secret  of 
consonants  and  vowels,  and  giving  to  each  con- 
sonantal sound  a  distinct  sign,  seemed  a  most  cum- 
bersome and  embarrassing  complication  to  the  ancient 
scholars — that  is  to  say,  after  the  time  arrived  when 
any  one  gave  such  an  idea  expression.  We  can 
imagine  them  saying:  "You  will  oblige  us  to  use  four 
signs  instead  of  one  to  write  such  an  elementary 
syllable  as  'bard,'  for  example.  Out  upon  such  end- 
less perplexity!"  Nor  is  such  a  suggestion  purely 
gratuitous,  for  it  is  an  historical  fact  that  the  old 
syllabary  continued  to  be  used  in  Babylon  hundreds 
of  years  after  the  alphabetical  system  had  been 
introduced.7  Custom  is  everything  in  establishing 
our  prejudices.  The  Japanese  to-day  rebel  against 
7  97 


A   HISTORY   OF   SCIENCE 

the   introduction    of    an    alphabet,   thinking   it   am- 
biguous. 

Yet,  in  the  end,  conservatism  always  yields,  and  so 
it  was  with  opposition  to  the  alphabet.  Once  the 
idea  of  the  consonant  had  been  firmly  grasped,  the 
old  syllabary  was  doomed,  though  generations  of  time 
might  be  required  to  complete  the  obsequies — genera- 
tions of  time  and  the  influence  of  a  new  nation.  We 
have  now  to  inquire  how  and  by  whom  this  advance 
was  made. 

THE   ALPHABET   ACHIEVED 

We  cannot  believe  that  any  nation  could  have 
vaulted  to  the  final  stage  of  the  simple  alphabetical 
writing  without  tracing  the  devious  and  difficult  way 
of  the  pictograph  and  the  syllabary.  It  is  possible, 
however,  for  a  cultivated  nation  to  build  upon  the 
shoulders  of  its  neighbors,  and,  profiting  by  the  ex- 
perience of  others,  to  make  sudden  leaps  upward  and 
onward.  And  this  is  seemingly  what  happened  in  the 
final  development  of  the  art  of  writing.  For  while 
the  Babylonians  and  Assyrians  rested  content  with 
their  elaborate  syllabary,  a  nation  on  either  side  of 
them,  geographically  speaking,  solved  the  problem, 
which  they  perhaps  did  not  even  recognize  as  a  problem ; 
wrested  from  their  syllabary  its  secret  of  consonants 
and  vowels,  and  by  adopting  an  arbitrary  sign  for  each 
consonantal  sound,  produced  that  most  wonderful  of 
human  inventions,  the  alphabet. 

The  two  nations  credited  with  this  wonderful 
achievement  are  the  Phoenicians  and  the  Persians. 
But  it  is  not  usually  conceded  that  the  two  are  en- 

98 


DEVELOPMENT  OF  THE  ALPHABET 

titled  to  anything  like  equal  credit.  The  Persians, 
probably  in  the  time  of  Cyrus  the  Great,  used  certain 
characters  of  the  Babylonian  script  for  the  con- 
struction of  an  alphabet;  but  at  this  time  the  Phoeni- 
cian alphabet  had  undoubtedly  been  in  use  for  some 
centuries,  and  it  is  more  than  probable  that  the 
Persian  borrowed  his  idea  of  an  alphabet  from  a 
Phoenician  source.  And  that,  of  course,  makes  all 
the  difference.  Granted  the  idea  of  an  alphabet,  it 
requires  no  great  reach  of  constructive  genius  to 
supply  a  set  of  alphabetical  characters;  though  even 
here,  it  may  be  added  parenthetically,  a  study  of  the 
development  of  alphabets  will  show  that  mankind  has 
all  along  had  a  characteristic  propensity  to  copy  rather 
than  to  invent. 

Regarding  the  Persian  alphabet-maker,  then,  as  a 
copyist  rather  than  a  true  inventor,  it  remains  to  turn 
attention  to  the  Phoenician  source  whence,  as  is  com- 
monly believed,  the  original  alphabet  which  became 
"  the  mother  of  all  existing  alphabets  "  came  into  being. 
It  must  be  admitted  at  the  outset  that  evidence  for  the 
Phoenician  origin  of  this  alphabet  is  traditional  rather 
than  demonstrative.  The  Phoenicians  were  the  great 
traders  of  antiquity;  undoubtedly  they  were  largely 
responsible  for  the  transmission  of  the  alphabet  from 
one  part  of  the  world  to  another,  once  it  had  been  in- 
vented. Too  much  credit  cannot  be  given  them  for 
this;  and  as  the  world  always  honors  him  who  makes 
an  idea  fertile  rather  than  the  originator  of  the  idea, 
there  can  be  little  injustice  in  continuing  to  speak  of 
the  Phoenicians  as  the  inventors  of  the  alphabet. 
But  the  actual  facts  of  the  case  will  probably  never 

99 


A   HISTORY   OF   SCIENCE 

be  known.  For  aught  we  know,  it  may  have  been 
some  dreamy-eyed  Israelite,  some  Babylonian  philoso- 
pher, some  Egyptian  mystic,  perhaps  even  some 
obscure  Cretan,  who  gave  to  the  hard-headed  Phceni- 
cian  trader  this,  conception  of  a  dismembered  syllable 
with  its  all-essential,  elemental,  wonder-working  conso- 
nant. But  it  is  futile  now  to  attempt  even  to  surmise 
on  such  unfathomable  details  as  these.  Suffice  it  that 
the  analysis  was  made;  that  one  sign  and  no  more 
was  adopted  for  each  consonantal  sound  of  the  Semitic 
tongue,  and  that  the  entire  cumbersome  mechanism  of 
the  Egyptian  and  Babylonian  writing  systems  was 
rendered  obsolescent.  These  systems  did  not  yield 
at  once,  to  be  sure ;  all  human  experience  would  have 
been  set  at  naught  had  they  done  so.  They  held  their 
own,  and  much  more  than  held  their  own,  for  many 
centuries.  After  the  Phoenicians  as  a  nation  had 
ceased  to  have  importance;  after  their  original  script 
had  been  endlessly  modified  by  many  alien  nations; 
after  the  original  alphabet  had  made  the  conquest  of 
all  civilized  Europe  and  of  far  outlying  portions  of  the 
Orient  —  the  Egyptian  and  Babylonian  scribes  con- 
tinued to  indite  their  missives  in  the  same  old  picto- 
graphs  and  syllables. 

The  inventive  thinker  must  have  been  struck  with 
amazement  when,  after  making  the  fullest  analysis  of 
speech-sounds  of  which  he  was  capable,  he  found  him- 
self supplied  with  only  a  score  or  so  of  symbols.  Yet 
as  regards  the  consonantal  sounds  he  had  exhausted 
the  resources  of  the  Semitic  tongue.  As  to  vowels,  he 
scarcely  considered  them  at  all.  It  seemed  to  him 
sufficient  to  use   one   symbol  for   each  consonantal 

ioo 


DEVELOPMENT  OF  THE  ALPHABET 

sound.  This  reduced  the  hitherto  complex  mechanism 
of  writing  to  so  simple  a  system  that  the  inventor  must 
have  regarded  it  with  sheer  delight.  On  the  other 
hand,  the  conservative  scholar  doubtless  thought  it 
distinctly  ambiguous.  In  truth,  it  must  be  admitted 
that  the  system  was  imperfect.  It  was  a  vast  im- 
provement on  the  old  syllabary,  but  it  had  its  draw- 
backs. Perhaps  it  had  been  made  a  bit  too  simple; 
certainly  it  should  have  had  symbols  for  the  vowel 
sounds  as  well  as  for  the  consonants.  Nevertheless, 
the  vowel-lacking  alphabet  seems  to  have  taken  the 
popular  fancy,  and  to  this  day  Semitic  people  have 
never  supplied  its  deficiencies  save  with  certain  dots 
and  points. 

Peoples  using  the  Aryan  speech  soon  saw  the  defect, 
and  the  Greeks  supplied  symbols  for  several  new  sounds 
at  a  very  early  day.8  But  there  the  matter  rested, 
and  the  alphabet  has  remained  imperfect.  For  the 
purposes  of  the  English  language  there  should  certainly 
have  been  added  a  dozen  or  more  new  characters.  It 
is  clear,  for  example,  that,  in  the  interest  of  explicit- 
ness,  we  should  have  a  separate  symbol  for  the  vowel 
sound  in  each  of  the  following  syllables:  bar,  bay, 
bann,  ball,  to  cite  a  single  illustration. 

There  is,  to  be  sure,  a  seemingly  valid  reason  for 
not  extending  our  alphabet,  in  the  fact  that  in  multi- 
plying syllables  it  would  be  difficult  to  select  characters 
at  once  easy  to  make  and  unambiguous.  Moreover,  the 
conservatives  might  point  out,  with  telling  effect,  that 
the  present  alphabet  has  proved  admirably  effective 
for  about  three  thousand  years.  Yet  the  fact  that 
our  dictionaries   supply  diacritical  marks   for   some 

IOI 


A   HISTORY   OF   SCIENCE 

thirty  vowels  sounds  to  indicate  the  pronunciation  of 
the  words  of  our  every-day  speech,  shows  how  we  let 
memoiy  and  guessing  do  the  work  that  might  rea- 
sonably be  demanded  of  a  really  complete  alphabet. 
But,  whatever  its  defects,  the  existing  alphabet  is  a 
marvellous  piece  of  mechanism,  the  result  of  thou- 
sands of  years  of  intellectual  effort.  It  is,  perhaps 
without  exception,  the  most  stupendous  invention  of 
the  human  intellect  within  historical  times — an  achieve- 
ment taking  rank  with  such  great  prehistoric  dis- 
coveries as  the  use  of  articulate  speech,  the  making 
of  a  fire,  and  the  invention  of  stone  implements,  of 
the  wheel  and  axle,  and  of  picture-writing.  It  made 
possible  for  the  first  time  that  education  of  the  masses 
upon  which  all  later  progress  of  civilization  was  so 
largely  to  depend. 


THE    BEGINNINGS    OF   GREEK    SCIENCE 

HERODOTUS,  the  Father  of  History,  tells  us  that 
once  upon  a  time  —  which  time,  as  the  modern 
computator  shows  us,  was  about  the  year  590  B.C. 
— a  war  had  risen  between  the  Lydians  and  the 
Medes  and  continued  five  years.  "In  these  years  the 
Medes  often  discomfited  the  Lydians  and  the  Lydians 
often  discomfited  the  Medes  (and  among  other  things 
they  fought  a  battle  by  night) ;  and  yet  they  still  car- 
ried on  the  war  with  equally  balanced  fortitude.  In 
the  sixth  year  a  battle  took  place  in  which  it  happened, 
when  the  fight  had  begun,  that  suddenly  the  day  be- 
came night.  And  this  change  of  the  day  Thales,  the 
Milesian,  had  foretold  to  the  Ionians,  laying  down  as 
a  limit  this  very  year  in  which  the  change  took  place. 
The  Lydians,  however,  and  the  Medes,  when  they  saw 
that  it  had  become  night  instead  of  day,  ceased  from 
their  fighting  and  were  much  more  eager,  both  of  them, 
that  peace  should  be  made  between  them." 

This  memorable  incident  occurred  while  Alyattus, 
father  of  Croesus,  was  king  of  the  Lydians.  The 
modern  astronomer,  reckoning  backward,  estimates 
this  eclipse  as  occurring  probably  May  25th,  585  b.c. 
The  date  is  important  as  fixing  a  mile-stone  in  the 
chronology  of  ancient  history,  but  it  is  doubly  mem- 
orable because  it  is  the  first  recorded  instance  of  a  pre- 

103 


A   HISTORY    OF   SCIENCE 

dieted  eclipse.  Herodotus,  who  tells  the  story,  was 
not  born  until  about  one  hundred  years  after  the  inci- 
dent occurred,  but  time  had  not  dimmed  the  fame  of 
the  man  who  had  performed  the  necromantic  feat  of 
prophecy.  Thales,  the  Milesian,  thanks  in  part  at 
least  to  this  accomplishment,  had  been  known  in  life 
as  first  on  the  list  of  the  Seven  Wise  Men  of  Greece, 
and  had  passed  into  history  as  the  father  of  Greek 
philosophy.  We  may  add  that  he  had  even  found 
wider  popular  fame  through  being  named  by  Hippo- 
lytus,  and  then  by  Father  ^Esop  as  the  philosopher 
who,  intent  on  studying  the  heavens,  fell  into  a  well; 
"whereupon,"  says  Hippolytus,  "a  maid  -  servant 
named  Thratta  laughed  at  him  and  said,  '  In  his  search 
for  things  in  the  sky  he  does  not  see  what  is  at  his  f eet. ' ' ' 
Such  citations  as  these  serve  to  bring  vividly  to 
mind  the  fact  that  we  are  entering  a  new  epoch  of 
thought.  Hitherto  our  studies  have  been  impersonal. 
Among  Egyptians  and  Babylonians  alike  we  have  had 
to  deal  with  classes  of  scientific  records,  but  we  have 
scarcely  come  across  a  single  name.  Now,  however, 
we  shall  begin  to  find  records  of  the  work  of  individual 
investigators.  In  general,  from  now  on,  we  shall  be 
able  to  trace  each  great  idea,  if  not  to  its  originator, 
at  least  to  some  one  man  of  genius  who  was  prominent 
in  bringing  it  before  the  world.  The  first  of  these 
vitalizers  of  thought,  who  stands  out  at  the  beginnings 
of  Greek  history,  is  this  same  Thales,  of  Miletus.  His 
is  not  a  very  sharply  defined  personality  as  we  look 
back  upon  it,  and  we  can  by  no  means  be  certain  that 
all  the  discoveries  which  are  ascribed  to  him  are  spe- 
cifically his.     Of  his  individuality  as  a  man  we  know 

104 


THE   BEGINNINGS   OF    GREEK   SCIENCE 

very  little.  It  is  not  even  quite  certain  as  to  where 
he  was  born;  Miletus  is  usually  accepted  as  his  birth- 
place, but  one  tradition  makes  him  by  birth  a  Pheni- 
cian.  It  is  not  at  all  in  question,  however,  that  by 
blood  he  was  at  least  in  part  an  Ionian  Greek.  It  will 
be  recalled  that  in  the  seventh  century  B.C.,  when 
Thales  was  born — and  for  a  long  time  thereafter — the 
eastern  shores  of  the  ^Egean  Sea  were  quite  as  promi- 
nently the  centre  of  Greek  influence  as  was  the  penin- 
sula of  Greece  itself.  Not  merely  Thales,  but  his  fol- 
lowers and  disciples,  Anaximander  and  Anaximenes, 
were  born  there.  So  also  was  Herodotas,  the  Father  of 
History,  not  to  extend  the  list.  There  is  nothing  anom- 
alous, then,  in  the  fact  that  Thales,  the  father  of  Greek 
thought,  was  born  and  passed  his  life  on  soil  that  was 
not  geographically  a  part  of  Greece ;  but  the  fact  has  an 
important  significance  of  another  kind.  Thanks  to 
his  environment,  Thales  was  necessarily  brought  more 
or  less  in  contact  with  Oriental  ideas.  There  was  close 
commercial  contact  between  the  land  of  his  nativity 
and  the  great  Babylonian  capital  off  to  the  east,  as 
also  with  Egypt.  Doubtless  this  association  was  of 
influence  in  shaping  the  development  of  Thales's  mind. 
Indeed,  it  was  an  accepted  tradition  throughout  clas- 
sical times  that  the  Milesian  philosopher  had  travelled 
in  Egypt,  and  had  there  gained  at  least  the  rudiments 
of  his  knowledge  of  geometry.  In  the  fullest  sense, 
then,  Thales  may  be  regarded  as  representing  a  link 
in  the  chain  of  thought  connecting  the  learning  of  the 
old  Orient  with  the  nascent  scholarship  of  the  new  Oc- 
cident. Occupying  this  position,  it  is  fitting  that  the 
personality   of   Thales   should   partake   somewhat   of 

io5 


A    HISTORY    OF   SCIENCE 

mystery;  that  the  scene  may  not  be  shifted  too  sud- 
denly from  the  vague,  impersonal  East  to  the  individ- 
ualism of  Europe. 

All  of  this,  however,  must  not  be  taken  as  casting 
any  doubt  upon  the  existence  of  Thales  as  a  real  per- 
son. Even  the  dates  of  his  life — 640  to  546  B.C.— 
may  be  accepted  as  at  least  approximately  trust- 
worthy; and  the  specific  discoveries  ascribed  to  him 
illustrate  equally  well  the  stage  of  development  of 
Greek  thought,  whether  Thales  himself  or  one  of  his 
immediate  disciples  were  the  discoverer.  We  have 
already  mentioned  the  feat  which  was  said  to  have 
given  Thales  his  great  reputation.  That  Thales  was 
universally  credited  with  having  predicted  the  famous 
eclipse  is  beyond  question.  That  he  actually  did  pre- 
dict it  in  any  precise  sense  of  the  word  is  open  to 
doubt.  At  all  events,  his  prediction  was  not  based 
upon  any  such  precise  knowledge  as  that  of  the  modern 
astronomer.  There  is,  indeed,  only  one  way  in  which 
he  could  have  foretold  the  eclipse,  and  that  is  through 
knowledge  of  the  regular  succession  of  preceding 
eclipses.  But  that  knowledge  implies  access  on  the 
part  of  some  one  to  long  series  of  records  of  practical 
observations  of  the  heavens.  Such  records,  as  we  have 
seen,  existed  in  Egypt  and  even  more  notably  in  Baby- 
lonia. That  these  records  were  the  source  of  the  in- 
formation which  established  the  reputation  of  Thales 
is  an  unavoidable  inference.  In  other  words,  the 
magical  prevision  of  the  father  of  Greek  thought  was 
but  a  reflex  of  Oriental  wisdom.  Nevertheless,  it  suf- 
ficed to  establish  Thales  as  the  father  of  Greek  astron- 
omy.    In  point  of  fact,  his  actual  astronomical  attain- 

106 


THE    BEGINNINGS   OF    GREEK   SCIENCE 

ments  would  appear  to  have  been  meagre  enough. 
There  is  nothing  to  show  that  he  gained  an  inkling  of 
the  true  character  of  the  solar  system.  He  did  not 
even  recognize  the  sphericity  of  the  earth,  but  held, 
still  following  the  Oriental  authorities,  that  the  world 
is  a  flat  disk.  Even  his  famous  cosmogonic  guess, 
according  to  which  water  is  the  essence  of  all  things 
and  the  primordial  element  out  of  which  the  earth  was 
developed,  is  but  an  elaboration  of  the  Babylonian 
conception. 

When  we  turn  to  the  other  field  of  thought  with 
which  the  name  of  Thales  is  associated — namely, 
geometry — we  again  find  evidence  of  the  Oriental  in- 
fluence. The  science  of  geometry,  Herodotus  assures 
us,  was  invented  in  Egypt.  It  was  there  an  eminently 
practical  science,  being  applied,  as  the  name  literally 
suggests,  to  the  measurement  of  the  earth's  surface. 
Herodotus  tells  us  that  the  Egyptians  were  obliged  to 
cultivate  the  science  because  the  periodical  inunda- 
tions washed  away  the  boundary-lines  between  their 
farms.  The  primitive  geometer,  then,  was  a  surveyor. 
The  Egyptian  records,  as  now  revealed  to  us,  show 
that  the  science  had  not  been  carried  far  in  the  land 
of  its  birth.  The  Egyptian  geometer  was  able  to 
measure  irregular  pieces  of  land  only  approximately. 
He  never  fully  grasped  the  idea  of  the  perpendicular  as 
the  true  index  of  measurement  for  the  triangle,  but 
based  his  calculations  upon  measurements  of  the  actual 
side  of  that  figure.  Nevertheless,  he  had  learned  to 
square  the  circle  with  a  close  approximation  to  the 
truth,  and,  in  general,  his  measurement  sufficed  for  all 
his  practical  needs.     Just  how  much  of  the  geometrical 

107 


A   HISTORY   OF   SCIENCE 

knowledge  which  added  to  the  fame  of  Thales  was  bor- 
rowed directly  from  the  Egyptians,  and  how  much  he 
actually  created  we  cannot  be  sure.  Nor  is  the  ques- 
tion raised  in  disparagement  of  his  genius.  Recep- 
tivity is  the  first .  prerequisite  to  progressive  thinking, 
and  that  Thales  reached  out  after  and  imbibed  por- 
tions of  Oriental  wisdom  argues  in  itself  for  the  crea- 
tive character  of  his  genius.  Whether  borrower  of 
originator,  however,  Thales  is  credited  with  the  ex- 
pression of  the  following  geometrical  truths: 

i.  That  the  circle  is  bisected  by  its  diameter. 

2.  That  the  angles  at  the  base  of  an  isosceles  triangle  are 
equal. 

3.  That  when  two  straight  lines  cut  each  other  the  vertical 
opposite  angles  are  equal. 

4.  That  the  angle  in  a  semicircle  is  a  right  angle. 

5.  That  one  side  and  one  acute  angle  of  a  right-angle  tri- 
angle determine  the  other  sides  of  the  triangle. 

It  was  by  the  application  of  the  last  of  these  princi- 
ples that  Thales  is  said  to  have  performed  the  really 
notable  feat  of  measuring  the  distance  of  a  ship  from 
the  shore,  his  method  being  precisely  the  same  in  prin- 
ciple as  that  by  which  the  guns  are  sighted  on  a  modern 
man-of-war.  Another  practical  demonstration  which 
Thales  was  credited  with  making,  and  to  which  also  his 
geometrical  studies  led  him,  was  the  measurement  of 
any  tall  object,  such  as  a  pyramid  or  building  or  tree, 
by  means  of  its  shadow.  The  method,  though  simple 
enough,  was  ingenious.  It  consisted  merely  in  ob- 
serving the  moment  of  the  day  when  a  perpendicular 
stick  casts  a  shadow  equal  to  its  own  length.  Ob- 
viously the  tree  or  monument  would  also  cast  a  shadow 

108 


THE   BEGINNINGS   OF    GREEK   SCIENCE 

equal  to  its  own  height  at  the  same  moment.  It  re- 
mains then  but  to  measure  the  length  of  this  shadow 
to  determine  the  height  of  the  object.  Such  feats  as 
this  evidence  the  practicality  of  the  genius  of  Thales. 
They  suggest  that  Greek  science,  guided  by  imagina- 
tion, was  starting  on  the  high-road  of  observation. 
We  are  told  that  Thales  conceived  for  the  first  time  the 
geometry  of  lines,  and  that  this,  indeed,  constituted  his 
real  advance  upon  the  Egyptians.  We  are  told  also 
that  he  conceived  the  eclipse  of  the  sun  as  a  purely 
natural  phenomenon,  and  that  herein  lay  his  advance 
upon  the  Chaldean  point  of  view.  But  if  this  be  true 
Thales  was  greatly  in  advance  of  his  time,  for  it  will  be 
recalled  that  fully  two  hundred  years  later  the  Greeks 
under  Nicias  before  Syracuse  were  so  disconcerted  by 
the  appearance  of  an  eclipse,  which  was  interpreted 
as  a  direct  omen  and  warning,  that  Nicias  threw  away 
the  last  opportunity  to  rescue  his  army.  Thucydides, 
it  is  true,  in  recording  this  fact  speaks  disparagingly 
of  the  superstitious  bent  of  the  mind  of  Nicias,  but 
Thucydides  also  was  a  man  far  in  advance  of  his 
time. 

All  that  we  know  of  the  psychology  of  Thales  is 
summed  up  in  the  famous  maxim,  "Know  thyself," 
a  maxim  which,  taken  in  connection  with  the  proven 
receptivity  of  the  philosopher's  mind,  suggests  to  us  a 
marvellously  rounded  personality. 

The  disciples  or  successors  of  Thales,  Anaximander 
and  Anaximenes,  were  credited  with  advancing  knowl- 
edge through  the  invention  or  introduction  of  the  sun- 
dial. We  may  be  sure,  however,  that  the  gnomon, 
which  is  the  rudimentary  sundial,  had  been  known 

109 


A   HISTORY    OF   SCIENCE 

and  used  from  remote  periods  in  the  Orient,  and  the 
most  that  is  probable  is  that  Anaximander  may  have 
elaborated  some  special  design,  possibly  the  bowl- 
shaped  sundial,  through  which  the  shadow  of  the 
gnomon  would  indicate  the  time.  The  same  philos- 
opher is  said  to  have  made  the  first  sketch  of  a  geo- 
graphical map,  but  this  again  is  a  statement  which, 
modern  researches  have  shown  to  be  fallacious,  since 
a  Babylonian  attempt  at  depicting  the  geography  of 
the  world  is  still  preserved  to  us  on  a  clay  tablet. 
Anaximander  may,  however,  have  been  the  first  Greek 
to  make  an  attempt  of  this  kind.  Here  again  the  in- 
fluence of  Babylonian  science  upon  the  germinating 
Western  thought  is  suggested. 

It  is  said  that  Anaximander  departed  from  Thales's 
conception  of  the  earth,  and,  it  may  be  added,  from  the 
Babylonian  conception  also,  in  that  he  conceived  it 
as  a  cylinder,  or  rather  as  a  truncated  cone,  the  upper 
end  of  which  is  the  habitable  portion.  This  concep- 
tion is  perhaps  the  first  of  these  guesses  through  which 
the  Greek  mind  attempted  to  explain  the  apparent 
fixity  of  the  earth.  To  ask  what  supports  the  earth 
in  space  is  most  natural,  but  the  answer  given  by 
Anaximander,  like  that  more  familiar  Greek  solution 
which  transformed  the  cone,  or  cylinder,  into  the  giant 
Atlas,  is  but  another  illustration  of  that  substitution 
of  unwarranted  inference  for  scientific  induction 
which  we  have  already  so  often  pointed  out  as  charac- 
teristic of  the  primitive  stages  of  thought. 

Anaximander  held  at  least  one  theory  which,  as 
vouched  for  by  various  copyists  and  commentators, 
entitles  him  to  be  considered  perhaps  the  first  teacher 

no 


THE   BEGINNINGS    OF    GREEK   SCIENCE 

of  the  idea  of  organic  evolution.  According  to  this 
idea,  man  developed  from  a  fishlike  ancestor,  "growing 
up  as  sharks  do  until  able  to  help  himself  and  then 
coming  forth  on  dry  land."  *  The  thought  here  ex- 
pressed finds  its  germ,  perhaps,  in  the  Babylonian  con- 
ception that  everything  came  forth  from  a  chaos  of 
waters.  Yet  the  fact  that  the  thought  of  Anaximan- 
der  has  come  down  to  posterity  through  such  various 
channels  suggests  that  the  Greek  thinker  had  got  far 
enough  away  from  the  Oriental  conception  to  make 
his  view  seem  to  his  contemporaries  a  novel  and  in- 
dividual one.  Indeed,  nothing  we  know  of  the  Oriental 
line  of  thought  conveys  any  suggestion  of  the  idea  of 
transformation  of  species,  whereas  that  idea  is  dis- 
tinctly formulated  in  the  traditional  views  of  Anaxi- 
mander. 


VI 
THE  EARLY  GREEK  PHILOSOPHERS  IN  ITALY 

DIOGENES  LAERTIUS  tells  a  story  about  a 
youth  who,  clad  in  a  purple  toga,  entered  the 
arena  at  the  Olympian  games  and  asked  to  compete 
with  the  other  youths  in  boxing.  He  was  derisively 
denied  admission,  presumably  because  he  was  beyond 
the  legitimate  age  for  juvenile  contestants.  Nothing" 
daunted,  the  youth  entered  the  lists  of  men,  and  turned 
the  laugh  on  his  critics  by  coming  off  victor.  The 
youth  who  performed  this  feat  was  named  Pythagoras. 
He  was  the  same  man,  if  we  may  credit  the  story,  who 
afterwards  migrated  to  Italy  and  became  the  founder 
of  the  famous  Crotonian  School  of  Philosophy;  the 
man  who  developed  the  religion  of  the  Orphic  mys- 
teries; who  conceived  the  idea  of  the  music  of  the 
spheres;  who  promulgated  the  doctrine  of  metem- 
psychosis; who  first,  perhaps,  of  all  men  clearly  con- 
ceived the  notion  that  this  world  on  which  we  live  is 
a  ball  which  moves  in  space  and  which  may  be  habit' 
able  on  every  side. 

A  strange  development  that  for  a  stripling  pugilist. 
But  we  must  not  forget  that  in  the  Greek  world  ath- 
letics held  a  peculiar  place.  The  chief  winner  of 
Olympian  games  gave  his  name  to  an  epoch  (the  en- 
suing Olympiad  of  four  years),  and  was  honored  al- 
most before  all  others  in  the  land.     A  sound  mind  in  a 

112 


EARLY  GREEK  PHILOSOPHERS  IN  ITALY 

sound  body  was  the  motto  of  the  day.  To  excel  in 
feats  of  strength  and  dexterity  was  an  accomplishment 
that  even  a  philosopher  need  not  scorn.  It  will  be  re- 
called that  ^Eschylus  distinguished  himself  at  the  bat- 
tle of  Marathon;  that  Thucydides,  the  greatest  of 
Greek  historians,  was  a  general  in  the  Peloponnesian 
War;  that  Xenophon,  the  pupil  and  biographer  of 
Socrates,  was  chiefly  famed  for  having  led  the  Ten 
Thousand  in  the  memorable  campaign  of  Cyrus  the 
Younger;  that  Plato  himself  was  credited  with  having 
shown  great  aptitude  in  early  life  as  a  wrestler.  If, 
then,  Pythagoras  the  philosopher  was  really  the  Py- 
thagoras who  won  the  boxing  contest,  we  may  sup- 
pose that  in  looking  back  upon  this  athletic  feat  from 
the  heights  of  his  priesthood — for  he  came  to  be  almost 
deified — he  regarded  it  not  as  an  indiscretion  of  his 
youth,  but  as  one  of  the  greatest  achievements  of  his 
life.  Not  unlikely  he  recalled  with  pride  that  he  was 
credited  with  being  no  less  an  innovator  in  athletics 
than  in  philosophy.  At  all  events,  tradition  credits 
him  with  the  invention  of  "  scientific  "  boxing.  Was  it 
he,  perhaps,  who  taught  the  Greeks  to  strike  a  rising 
and  swinging  blow  from  the  hip,  as  depicted  in  the 
famous  metopes  of  the  Parthenon  ?  If  so,  the  innova- 
tion of  Pythagoras  was  as  little  heeded  in  this  regard 
in  a  subsequent  age  as  was  his  theory  of  the  motion  of 
the  earth;  for  to  strike  a  swinging  blow  from  the  hip, 
rather  than  from  the  shoulder,  is  a  trick  which  the 
pugilist  learned  anew  in  our  own  day. 

But  enough  of  pugilism  and  of  what,  at  best,  is  a 
doubtful  tradition.  Our  concern  is  with  another 
"  science"  than  that  of  the  arena.     We  must  follow  the 

8  113 


A   HISTORY   OF   SCIENCE 

purple-robed  victor  to  Italy — if,  indeed,  we  be  not  over- 
credulous  in  accepting  the  tradition — and  learn  of  tri- 
umphs of  a  different  kind  that  have  placed  the  name  of 
Pythagoras  high  on  the  list  of  the  fathers  of  Grecian 
thought.  To  Italy?  Yes,  to  the  western  limits  of 
the  Greek  world.  Here  it  was,  beyond  the  confines  of 
actual  Greek  territory,  that  Hellenic  thought  found  its 
second  home,  its  first  home  being,  as  we  have  seen,  in 
Asia  Minor.  Pythagoras,  indeed,  to  whom  we  have 
just  been  introduced,  was  born  on  the  island  of  Samos, 
which  lies  near  the  coast  of  Asia  Minor,  but  he  prob- 
ably migrated  at  an  early  day  to  Crotona,  in  Italy. 
There  he  lived,  taught,  and  developed  his  philosophy 
until  rather  late  in  life,  when,  having  incurred  the  dis- 
pleasure of  his  fellow-citizens,  he  suffered  the  not 
unusual  penalty  of  banishment. 

Of  the  three  other  great  Italic  leaders  of  thought  of 
the  early  period,  Xenophanes  came  rather  late  in  life  to 
Elea  and  founded  the  famous  Eleatic  School,  of  which 
Parmenides  became  the  most  distinguished  ornament. 
These  two  were  Ionians,  and  they  lived  in  the  sixth 
century  before  our  era.  Empedocles,  the  Sicilian, 
was  of  Doric  origin.  He  lived  about  the  middle  of  the 
fifth  century  b.c,  at  a  time,  therefore,  when  Athens 
had  attained  a  position  of  chief  glory  among  the  Greek 
states ;  but  there  is  no  evidence  that  Empedocles  ever 
visited  that  city,  though  it  was  rumored  that  he  return- 
ed to  the  Peloponnesus  to  die.  The  other  great  Italic 
philosophers  just  named,  living,  as  we  have  seen,  in 
the  previous  century,  can  scarcely  have  thought  of 
Athens  as  a  centre  of  Greek  thought.  Indeed,  the  very 
fact  that  these  men  lived  in  Italy  made  that  peninsula, 

114 


PYTHAGORAS 
(From  an  old  print.) 


EARLY   GREEK   PHILOSOPHERS  IN   ITALY 

rather  than  the  mother-land  of  Greece,  the  centre  of 
Hellenic  influence.  But  all  these  men,  it  must  con- 
stantly be  borne  in  mind,  were  Greeks  by  birth  and 
language,  fully  recognized  as  such  in  their  own  time 
and  by  posterity.  Yet  the  fact  that  they  lived  in  a 
land  which  was  at  no  time  a  part  of  the  geographical 
territory  of  Greece  must  not  be  forgotten.  They,  or 
their  ancestors  of  recent  generations,  had  been  pioneers 
among  those  venturesome  colonists  who  reached  out 
into  distant  portions  of  the  world,  and  made  homes 
for  themselves  in  much  the  same  spirit  in  which  col- 
onists from  Europe  began  to  populate  America  some 
two  thousand  years  later.  In  general,  colonists  from 
the  different  parts  of  Greece  localized  themselves  some- 
what definitely  in  their  new  homes;  yet  there  must 
naturally  have  been  a  good  deal  of  commingling  among 
the  various  families  of  pioneers,  and,  to  a  certain  ex- 
tent, a  mingling  also  with  the  earlier  inhabitants  of 
the  country.  This  racial  mingling,  combined  with  the 
well-known  vitalizing  influence  of  the  pioneer  life,  led, 
we  may  suppose,  to  a  more  rapid  and  more  varied 
development  than  occurred  among  the  home-staying 
Greeks.  In  proof  of  this,  witness  the  remarkable 
schools  of  philosophy  which,  as  we  have  seen,  were 
thus  developed  at  the  confines  of  the  Greek  world,  and 
which  were  presently  to  invade  and,  as  it  were,  take 
by  storm  the  mother-country  itself. 

As  to  the  personality  of  these  pioneer  philosophers 
of  the  West,  our  knowledge  is  for  the  most  part  more  or 
less  traditional.  What  has  been  said  of  Thales  may 
be  repeated,  in  the  main,  regarding  Pythagoras,  Par- 
menides,  and  Empedocles.    That  they  were  real  per- 

"5 


A   HISTORY   OF   SCIENCE 

sons  is  not  at  all  in  question,  but  much  that  is  merely 
traditional  has  come  to  be  associated  with  their  names. 
Pythagoras  was  the  senior,  and  doubtless  his  ideas 
may  have  influenced  the  others  more  or  less,  though 
each  is  usually  spoken  of  as  the  founder  of  an  inde- 
pendent school.  Much  confusion  has  all  along  existed, 
however,  as  to  the  precise  ideas  which  were  to  be  as- 
cribed to  each  of  the  leaders.  Numberless  commenta- 
tors, indeed,  have  endeavored  to  pick  out  from  among 
the  traditions  of  antiquity,  aided  by  such  fragments 
of  the  writing  of  the  philosophers  as  have  come  down 
to  us,  the  particular  ideas  that  characterized  each 
thinker,  and  to  weave  these  ideas  into  systems.  But 
such  efforts,  notwithstanding  the  mental  energy  that 
has  been  expended  upon  them,  were,  of  necessity, 
futile,  since,  in  the  first  place,  the  ancient  philosophers 
themselves  did  not  specialize  and  systematize  their 
ideas  according  to  modern  notions,  and,  in  the  second 
place,  the  records  of  their  individual  teachings  have 
been  too  scantily  preserved  to  serve  for  the  purpose  of 
classification.  It  is  freely  admitted  that  fable  has 
woven  an  impenetrable  mesh  of  contradictions  about 
the  personalities  of  these  ancient  thinkers,  and  it  would 
be  folly  to  hope  that  this  same  artificer  had  been  less 
busy  with  their  beliefs  and  theories.  When  one  reads 
that  Pythagoras  advocated  an  exclusively  vegetable 
diet,  yet  that  he  was  the  first  to  train  athletes  on  meat 
diet ;  that  he  sacrificed  only  inanimate  things,  yet  that 
he  offered  up  a  hundred  oxen  in  honor  of  his  great  dis- 
covery regarding  the  sides  of  a  triangle,  and  such  like 
inconsistencies  in  the  same  biography,  one  gains  a 
realizing  sense  of  the  extent  to  which  diverse  traditions 

116 


EARLY   GREEK   PHILOSOPHERS   IN    ITALY 

enter  into  the  story  as  it  has  come  down  to  us.  And 
yet  we  must  reflect  that  most  men  change  their  opin- 
ions in  the  course  of  a  long  lifetime,  and  that  the  an- 
tagonistic reports  may  both  be  true. 

True  or  false,  these  fables  have  an  abiding  interest, 
since  they  prove  the  unique  and  extraordinary  char- 
acter of  the  personality  about  which  they  are  woven. 
The  alleged  witticisms  of  a  Whistler,  in  our  own  day, 
were  doubtless,  for  the  most  part,  quite  unknown  to 
Whistler  himself,  yet  they  never  would  have  been 
ascribed  to  him  were  they  not  akin  to  witticisms  that 
he  did  originate — were  they  not,  in  short,  typical  ex- 
pressions of  his  personality.  And  so  of  the  heroes  of 
the  past.  "  It  is  no  ordinary  man,"  said  George  Henry 
Lewes,  speaking  of  Pythagoras,  "whom  fable  exalts 
into  the  poetic  region.  Whenever  you  find  romantic 
cr  miraculous  deeds  attributed,  be  certain  that  the 
hero  was  great  enough  to  maintain  the  weight  of  the 
crown  of  this  fabulous  glory."1  We  may  not  doubt, 
then,  that  Pythagoras,  Parmenides,  and  Empedocles, 
with  whose  names  fable  was  so  busy  throughout  an- 
tiquity, were  men  of  extraordinary  personality.  We 
are  here  chiefly  concerned,  however,  neither  with  the 
personality  of  the  man  nor  yet  with  the  precise  doc- 
trines which  each  one  of  them  taught.  A  knowledge 
of  the  latter  would  be  interesting  were  it  attainable, 
but  in  the  confused  state  of  the  reports  that  have  come 
down  to  us  we  cannot  hope  to  be  able  to  ascribe  each 
idea  with  precision  to  its  proper  source.  At  best  we 
can  merely  outline,  even  here  not  too  precisely,  the 
scientific  doctrines  which  the  Italic  philosophers  as  a 
whole  seem  to  have  advocated. 

117 


A   HISTORY   OF    SCIENCE 

First  and  foremost,  there  is  the  doctrine  that  the 
earth  is  a  sphere.  Pythagoras  is  said  to  have  been  the 
first  advocate  of  this  theory ;  but,  unfortunately,  it  is 
reported  also  that  Parmenides  was  its  author.  This 
rivalship  for  the  discovery  of  an  important  truth  we 
shall  see  repeated  over  and  over  in  more  recent  times. 
Could  we  know  the  whole  truth,  it  would  perhaps  ap- 
pear that  the  idea  of  the  sphericity  of  the  earth  was 
originated  long  before  the  time  of  the  Greek  philoso- 
phers. But  it  must  be  admitted  that  there  is  no  record 
of  any  sort  to  giye  tangible  support  to  such  an  assump- 
tion. So  far  as  we  can  ascertain,  no  Egyptian  or 
Babylonian  astronomer  ever  grasped  the  wonderful 
conception  that  the  earth  is  round.  That  the  Italic 
Greeks  should  have  conceived  that  idea  was  perhaps 
not  so  much  because  they  were  astronomers  as  because 
they  were  practical  geographers  and  geometers.  Py- 
thagoras, as  we  have  noted,  was  born  at  Samos,  and, 
therefore,  made  a  relatively  long  sea  voyage  in  passing 
to  Italy.  Now,  as  every  one  knows,  the  most  simple 
and  tangible  demonstration  of  the  convexity  of  the 
earth's  surface  is  furnished  by  observation  of  an  ap- 
proaching ship  at  sea.  On  a  clear  day  a  keen  eye  may 
discern  the  mast  and  sails  rising  gradually  above  the 
horizon,  to-  be  followed  in  due  course  by  the  hull. 
Similarly,  on  approaching  the  shore,  high  objects  be- 
come visible  before  those  that  lie  nearer  the  water. 
It  is  at  least  a  plausible  supposition  that  Pythagoras 
may  have  made  such  observations  as  these  during  the 
voyage  in  question,  and  that  therein  may  lie  the  germ 
of  that  wonderful  conception  of  the  world  as  a  sphere. 

To  what  extent  further  proof,  based  on  the  fact  that 

118 


EARLY   GREEK    PHILOSOPHERS    IN    ITALY 

the  earth's  shadow  when  the  moon  is  eclipsed  is  always 
convex,  may  have  been  known  to  Pythagoras  we  can- 
not say.  There  is  no  proof  that  any  of  the  Italic  phi- 
losophers made  extensive  records  of  astronomical  ob- 
servations as  did  the  Egyptians  and  Babylonians ;  but 
we  must  constantly  recall  that  the  writings  of  class- 
ical antiquity  have  been  almost  altogether  destroyed. 
The  absence  of  astronomical  records  is,  therefore,  no 
proof  that  such  records  never  existed.  Pythagoras,  it 
should  be  said,  is  reported  to  have  travelled  in  Egypt, 
and  he  must  there  have  gained  an  inkling  of  astronom- 
ical methods.  Indeed,  he  speaks  of  himself  specifically, 
in  a  letter  quoted  by  Diogenes,  as  one  who  is  accus- 
tomed to  study  astronomy.  Yet  a  later  sentence  of 
the  letter,  which  asserts  that  the  philosopher  is  not  al- 
ways occupied  about  speculations  of  his  own  fancy, 
suggesting,  as  it  does,  the  dreamer  rather  than  the  ob- 
server, gives  us  probably  a  truer  glimpse  into  the  phi- 
losopher's mind.  There  is,  indeed,  reason  to  suppose 
that  the  doctrine  of  the  sphericity  of  the  earth  appealed 
to  Pythagoras  chiefly  because  it  accorded  with  his 
conception  that  the  sphere  is  the  most  perfect  solid, 
just  as  the  circle  is  the  most  perfect  plane  surface.  Be 
that  as  it  may,  the  fact  remains  that  we  have  here,  as 
far  as  we  can  trace  its  origin,  the  first  expression  of  the 
scientific  theory  that  the  earth  is  round.  Had  the 
Italic  philosophers  accomplished  nothing  more  than 
this,  their  accomplishment  would  none  the  less  mark 
an  epoch  in  the  progress  of  thought. 

That  Pythagoras  was  an  observer  of  the  heavens  is 
further  evidenced  by  the  statement  made  by  Diogenes, 
on  the  authority  of  Parmenides,  that  Pythagoras  was 

119 


A   HISTORY   OF   SCIENCE 

the  first  person  who  discovered  or  asserted  the  identity 
of  Hesperus  and  Lucifer — that  is  to  say,  of  the  morning 
and  the  evening  star.  This  was  really  a  remarkable 
discovery,  and  one  that  was  no  doubt  instrumental 
later  on  in  determining  that  theory  of  the  mechanics 
of  the  heavens  which  we  shall  see  elaborated  presently. 
To  have  made  such  a  discovery  argues  again  for  the 
practicality  of  the  mind  of  Pythagoras.  His,  indeed, 
would  seem  to  have  been  a  mind  in  which  practical 
common-sense  was  strangely  blended  with  the  capacity 
for  wide  and  imaginative  generalization.  As  further 
evidence  of  his  practicality,  it  is  asserted  that  he  was 
the  first  person  who  introduced  measures  and  weights 
among  the  Greeks,  this  assertion  being  made  on  the 
authority  of  Aristoxenus.  It  will  be  observed  that  he 
is  said  to  have  introduced,  not  to  have  invented, 
weights  and  measures,  a  statement  which  suggests  a 
knowledge  on  the  part  of  the  Greeks  that  weights  and 
measures  were  previously  employed  in  Egypt  and 
Babylonia. 

The  mind  that  could  conceive  the  world  as  a  sphere 
and  that  interested  itself  in  weights  and  measures 
was,  obviously,  a  mind  of  the  visualizing  type.  It  is 
characteristic  of  this  type  of  mind  to  be  interested  in 
the  tangibilities  of  geometry,  hence  it  is  not  surprising 
to  be  told  that  Pythagoras  "  carried  that  science  to 
perfection."  The  most  famous  discovery  of  Pythag- 
oras in  this  field  was  that  the  square  of  the  hypotenuse 
of  a  right-angled  triangle  is  equal  to  the  squares  of  the 
other  sides  of  the  triangle.  We  have  already  noted 
the  fable  that  his  enthusiasm  over  this  discovery  led 
him  to  sacrifice  a  hecatomb.     Doubtless  the  story  is 

120 


EARLY  GREEK   PHILOSOPHERS   IN  ITALY 

apocryphal,  but  doubtless,  also,  it  expresses  the  truth 
as  to  the  fervid  joy  with  which  the  philosopher  must 
have  contemplated  the  results  of  his  creative  imagina- 
tion. 

No  line  alleged  to  have  been  written  by  Pythagoras 
has  come  down  to  us.  We  are  told  that  he  refrained 
from  publishing  his  doctrines,  except  by  word  of 
mouth.  "The  Lucanians  and  the  Peucetians,  and  the 
Messapians  and  the  Romans,"  we  are  assured,  "  flocked 
around  him,  coming  with  eagerness  to  hear  his  dis- 
courses; no  fewer  than  six  hundred  came  to  him 
every  night ;  and  if  any  one  of  them  had  ever  been  per- 
mitted to  see  the  master,  they  wrote  of  it  to  their  friends 
as  if  they  had  gained  some  great  advantage."  Never- 
theless, we  are  assured  that  until  the  time  of  Philolaus 
no  doctrines  of  Pythagoras  were  ever  published,  to 
which  statement  it  is  added  that  "  when  the  three  cele- 
brated books  were  published,  Plato  wrote  to  have  them 
purchased  for  him  for  a  hundred  minas." 2  But  if  such 
books  existed,  they  are  lost  to  the  modern  world,  and 
we  are  obliged  to  accept  the  assertions  of  relatively 
late  writers  as  to  the  theories  of  the  great  Cro- 
tonian. 

Perhaps  we  cannot  do  better  than  quote  at  length 
from  an  important  summary  of  the  remaining  doctrines 
of  Pythagoras,  which  Diogenes  himself  quoted  from 
the  work  of  a  predecessor.3  Despite  its  somewhat 
inchoate  character,  this  summary  is  a  most  remarkable 
one,  as  a  brief  analysis  of  its  contents  will  show.  It 
should  be  explained  that  Alexander  (whose  work  is 
now  lost)  is  said  to  have  found  these  dogmas  set  down 
in  the  commentaries  of  Pythagoras.     If  this  assertion 

121 


A   HISTORY   OF   SCIENCE 

be  accepted,  we  are  brought  one  step  nearer  the  phi- 
losopher himself.     The  summary  is  as  follows: 

"That  the  monad  was  the  beginning  of  everything. 
From  the  monad  proceeds  an  indefinite  duad,  which  is 
subordinate  to  the  monad  as  to  its  cause.  That  from 
the  monad  and  the  indefinite  duad  proceed  numbers. 
And  from  numbers  signs.  And  from  these  last,  lines 
of  which  plane  figures  consist.  And  from  plane  figures 
are  derived  solid  bodies.  And  from  solid  bodies  sen- 
sible bodies,  of  which  last  there  are  four  elements — fire, 
water,  earth,  and  air.  And  that  the  world,  which  is 
indued  with  life  and  intellect,  and  which  is  of  a  spher- 
ical figure,  having  the  earth,  which  is  also  spherical, 
and  inhabited  all  over  in  its  centre,4  results  from  a  com- 
bination of  these  elements,  and  derives  its  motion  from 
them;  and  also  that  there  are  antipodes,  and  that 
what  is  below,  as  respects  us,  is  above  in  respect  of 
them. 

"He  also  taught  that  light  and  darkness,  and  cold 
and  heat,  and  dryness  and  moisture,  were  equally  di- 
vided in  the  world ;  and  that  while  heat  was  predomi- 
nant it  was  summer;  while  cold  had  the  mastery,  it 
was  winter;  when  dryness  prevailed,  it  was  spring;  and 
when  moisture  preponderated,  winter.  And  while  all 
these  qualities  were  on  a  level,  then  was  the  loveliest 
season  of  the  year ;  of  which  the  flourishing  spring  was 
the  wholesome  period,  and  the  season  of  autumn  the 
most  pernicious  one.  Of  the  day,  he  said  that  the 
flourishing  period  was  the  morning,  and  the  fading  one 
the  evening ;  on  which  account  that  also  was  the  least 
healthy  time. 

122 


EARLY  GREEK    PHILOSOPHERS    IN  ITALY 

"Another  of  his  theories  was  that  the  air  around 
the  earth  was  immovable  and  pregnant  with  disease, 
and  that  everything  in  it  was  mortal ;  but  that  the  up- 
per air  was  in  perpetual  motion,  and  pure  and  salubri- 
ous, and  that  everything  in  that  was  immortal,  and 
on  that  account  divine.  And  that  the  sun  and  the 
moon  and  the  stars  were  all  gods ;  for  in  them  the  warm 
principle  predominates  which  is  the  cause  of  life.  And 
that  themoon  derives  its  light  from  the  sun.  And 
that  there  is  a  relationship  between  men  and  the  gods, 
because  men  partake  of  the  divine  principle ;  on  which 
account,  also,  God  exercises  his  providence  for  our  ad- 
vantage. Also,  that  Fate  is  the  cause  of  the  arrange- 
ment of  the  world  both  generally  and  particularly. 
Moreover,  that  a  ray  from  the  sun  penetrated  both  the 
cold  aether  and  the  dense  aether;  and  they  call  the  air 
the  cold  (Ether,  and  the  sea  and  moisture  they  call  the 
dense  (Biker.  And  this  ray  descends  into  the  depths, 
and  in  this  way  vivifies  everything.  And  everything 
which  partakes  of  the  principle  of  heat  lives,  on  which 
account,  also,  plants  are  animated  beings;  but  that  all 
living  things  have  not  necessarily  souls.  And  that 
the  soul  is  a  something  torn  off  from  the  aether,  both 
warm  and  cold,  from  its  partaking  of  the  cold  aether. 
And  that  the  soul  is  something  different  from  life. 
Also,  that  it  is  immortal,  because  that  from  which  it 
has  been  detached  is  immortal. 

"Also,  that  animals  are  born  from  one  another  by 
seeds,  and  that  it  is  impossible  for  there  to  be  any 
spontaneous  production  by  the  earth.  And  that  seed 
is  a  drop  from  the  brain  which  contains  in  itself  a 
warm  vapor;   and  that  when  this  is  applied  to  the 

123 


A   HISTORY   OF   SCIENCE 

womb  it  transmits  virtue  and  moisture  and  blood 
from  the  brain,  from  which  flesh  and  sinews  and  bones 
and  hair  and  the  whole  body  are  produced.  And 
from  the  vapor  is  produced  the  soul,  and  also  sensa- 
tion. And  that  the  infant  first  becomes  a  solid  body 
at  the  end  of  forty  days;  but,  according  to  the  prin- 
ciples of  harmony,  it  is  not  perfect  till  seven,  or  per- 
haps nine,  or  at  most  ten  months,  and  then  it  is 
brought  forth.  And  that  it  contains  in  itself  all  the 
principles  of  life,  which  are  all  connected  together,  and 
by  their  union  and  combination  form  a  harmonious 
whole,  each  of  them  developing  itself  at  the  appointed 
time. 

"  The  senses  in  general,  and  especially  the  sight,  are  a 
vapor  of  excessive  warmth,  and  on  this  account  a  man 
is  said  to  see  through  air  and  through  water.  For  the 
hot  principle  is  opposed  by  the  cold  one ;  since,  if  the 
vapor  in  the  eyes  were  cold,  it  would  have  the  same 
temperature  as  the  air,  and  so  would  be  dissipated. 
As  it  is,  in  some  passages  he  calls  the  eyes  the  gates 
of  the  sun;  and  he  speaks  in  a  similar  manner  of 
hearing  and  of  the  other  senses. 

"  He  also  says  that  the  soul  of  man  is  divided  into 
three  parts:  into  intuition  and  reason  and  mind,  and 
that  the  first  and  last  divisions  are  found  also  in  other 
animals,  but  that  the  middle  one,  reason,  is  only  found 
in  man.  And  that  the  chief  abode  of  the  soul  is  in 
those  parts  of  the  body  which  are  between  the  heart 
and  the  brain.  And  that  that  portion  of  it  which  is  in 
the  heart  is  the  mind ;  but  that  deliberation  and  reason 
reside  in  the  brain. 

"Moreover,  that  the  senses  are  drops  from  them; 

124 


EARLY  GREEK  PHILOSOPHERS  IN  ITALY 

and  that  the  reasoning  sense  is  immortal,  but  the  others 
are  mortal.  And  that  the  soul  is  nourished  by  the 
blood;  and  that  reasons  are  the  winds  of  the  soul. 
That  it  is  invisible,  and  so  are  its  reasons,  since  the 
aether  itself  is  invisible.  That  the  links  of  the  soul  are 
the  veins  and  the  arteries  and  the  nerves.  But  that 
when  it  is  vigorous,  and  is  by  itself  in  a  quiescent  state, 
then  its  links  are  words  and  actions.  That  when  it  is 
cast  forth  upon  the  earth  it  wanders  about,  resem- 
bling the  body.  Moreover,  that  Mercury  is  the  stew- 
ard of  the  souls,  and  that  on  this  account  he  has 
the  name  of  Conductor,  and  Commercial,  and  Infernal, 
since  it  is  he  who  conducts  the  souls  from  their  bodies, 
and  from  earth  and  sea ;  and  that  he  conducts  the  pure 
souls  to  the  highest  region,  and  that  he  does  not  allow 
the  impure  ones  to  approach  them,  nor  to  come  near  one 
another,  but  commits  them  to  be  bound  in  indissoluble 
fetters  by  the  Furies.  The  Pythagoreans  also  assert 
that  the  whole  air  is  full  of  souls,  and  that  these  are 
those  which  are  accounted  damons  and  heroes.  Also, 
that  it  is  by  them  that  dreams  are  sent  among  men,  and 
also  the  tokens  of  disease  and  health;  these  last,  too, 
being  sent  not  only  to  men,  but  to  sheep  also,  and  other 
cattle.  Also  that  it  is  they  who  are  concerned  with 
purifications  and  expiations  and  all  kinds  of  divination 
and  oracular  predictions,  and  things  of  that  kind."5 

A  brief  consideration  of  this  summary  of  the  doc- 
trines of  Pythagoras  will  show  that  it  at  least  outlines 
a  most  extraordinary  variety  of  scientific  ideas,  (i) 
There  is  suggested  a  theory  of  monads  and  the  con- 
ception of  the  development  from  simple  to  more  com- 

I25 


A    HISTORY    OF    SCIENCE 

plex  bodies,  passing  through  the  stages  of  lines,  plain 
figures,  and  solids  to  sensible  bodies.  (2)  The  doctrine 
of  the  four  elements — fire,  water,  earth,  and  air — as  the 
basis  of  all  organisms  is  put  forward.  (3)  The  idea, 
not  merely  of  the  sphericity  of  the  earth,  but  an  ex- 
plicit conception  of  the  antipodes,  is  expressed.  (4) 
A  conception  of  the  sanitary  influence  of  the  air  is 
clearly  expressed.  (5)  An  idea  of  the  problems  of 
generation  and  heredity  is  shown,  together  with  a  dis- 
tinct disavowal  of  the  doctrine  of  spontaneous  gen- 
eration— a  doctrine  which,  it  may  be  added,  remained 
in  vogue,  nevertheless,  for  some  twenty-four  hundred 
years  after  the  time  of  Pythagoras.  (6)  A  remarkable 
analysis  of  mind  is  made,  and  a  distinction  between 
animal  minds  and  the  human  mind  is  based  on  this 
analysis.  The  physiological  doctrine  that  the  heart 
is  the  organ  of  one  department  of  mind  is  offset  by  the 
clear  statement  that  the  remaining  factors  of  mind 
reside  in  the  brain.  This  early  recognition  of  brain 
as  the  organ  of  mind  must  not  be  forgotten  in  our  later 
studies.  It  should  be  recalled,  however,  that  a  Cro- 
tonian  physician,  Alemaean,  a  younger  contemporary 
of  Pythagoras,  is  also  credited  with  the  same  theory. 
(7)  A  knowledge  of  anatomy  is  at  least  vaguely  fore- 
shadowed in  the  assertion  that  veins,  arteries,  and 
nerves  are  the  links  of  the  soul.  In  this  connection  it 
should  be  recalled  that  Pythagoras  was  a  practical 
physician. 

As  against  these  scientific  doctrines,  however,  some 
of  them  being  at  least  remarkable  guesses  at  the  truth, 
attention  must  be  called  to  the  concluding  paragraph 
of  our  quotation,  in  which  the  old  familiar  daemonology 

126 


EARLY  GREEK   PHILOSOPHERS   IN   ITALY 

is  outlined,  quite  after  the  Oriental  fashion.  We 
shall  have  occasion  to  say  more  as  to  this  phase  of  the 
subject  later  on.  Meantime,  before  leaving  Pythag- 
oras, let  us  note  that  his  practical  studies  of  humanity 
led  him  to  assert  the  doctrine  that  "the  property  of 
friends  is  common,  and  that  friendship  is  equality." 
His  disciples,  we  are  told,  used  to  put  all  their  posses- 
sions together  in  one  store  and  use  them  in  common. 
Here,  then,  seemingly,  is  the  doctrine  of  communism 
put  to  the  test  of  experiment  at  this  early  day.  If  it 
seem  that  reference  to  this  carries  us  beyond  the 
bounds  of  science,  it  may  be  replied  that  questions  such 
as  this  will  not  lie  beyond  the  bounds  of  the  science  of 
the  near  future. 

XENOPHANES    AND   PARMENIDES 

There  is  a  whimsical  tale  about  Pythagoras,  accord- 
ing to  which  the  philosopher  was  wont  to  declare  that 
in  an  earlier  state  he  had  visited  Hades,  and  had  there 
seen  Homer  and  Hesiod  tortured  because  of  the  ab- 
surd things  they  had  said  about  the  gods.  Apocry- 
phal or  otherwise,  the  tale  suggests  that  Pythagoras 
was  an  agnostic  as  regards  the  current  Greek  religion 
of  his  time.  The  same  thing  is  perhaps  true  of  most 
of  the  great  thinkers  of  this  earliest  period.  But  one 
among  them  was  remembered  in  later  times  as  having 
had  a  peculiar  aversion  to  the  anthropomorphic  concep- 
tions of  his  fellows.  This  was  Xenophanes,  who  was 
born  at  Colophon  probably  about  the  year  580  B.C.,  and 
who,  after  a  life  of  wandering,  settled  finally  in  Italy 
and  became  the  founder  of  the  so-called  Eleatic  School. 

A  few  fragments  of  the  philosophical  poem  in  which 

127 


A    HISTORY   OF   SCIENCE 

Xenophanes  expressed  his  views  have  come  down  to 
us,  and  these  fragments  include  a  tolerably  definite 
avowal  of  his  faith.  "  God  is  one  supreme  among  gods 
and  men,  and  not  like  mortals  in  body  or  in  mind," 
says  Xenophanes.  Again  he  asserts  that  "  mortals  sup- 
pose that  the  gods  are  born  (as  they  themselves  are), 
that  they  wear  man's  clothing  and  have  human  voice 
and  body;  but,"  he  continues,  "if  cattle  or  lions  had 
hands  so  as  to  paint  with  their  hands  and  produce 
works  of  art  as  men  do,  they  would  paint  their  gods 
and  give  them  bodies  in  form  like  their  own — horses 
like  horses,  cattle  like  cattle."  Elsewhere  he  says,  with 
great  acumen:  "There  has  not  been  a  man,  nor  will 
there  be,  who  knows  distinctly  what  I  say  about  the 
gods  or  in  regard  to  all  things.  For  even  if  one  chance 
for  the  most  part  to  say  what  is  true,  still  he  would 
not  know;  but  every  one  thinks  that  he  knows."6 

In  the  same  spirit  Xenophanes  speaks  of  the  battles 
of  Titans,  of  giants,  and  of  centaurs  as  "fictions  of 
former  ages."  All  this  tells  of  the  questioning  spirit 
which  distinguishes  the  scientific  investigator.  Pre- 
cisely whither  this  spirit  led  him  we  do  not  know,  but 
the  writers  of  a  later  time  have  preserved  a  tradition 
regarding  a  belief  of  Xenophanes  that  perhaps  en- 
titles him  to  be  considered  the  father  of  geology.  Thus 
Hippolytus  records  that  Xenophanes  studied  the  fos- 
sils to  be  found  in  quarries,  and  drew  from  their  ob- 
servation remarkable  conclusions.  His  words  are  as 
follows:  "Xenophanes  believes  that  once  the  earth 
was  mingled  with  the  sea,  but  in  the  course  of  time  it 
became  freed  from  moisture;  and  his  proofs  are  such 
as  these:  that  shells  are  found  in  the   midst  of  the 

128 


EARLY  GREEK   PHILOSOPHERS   IN  ITALY 

land  and  among  the  mountains,  that  in  the  quarries 
of  Syracuse  the  imprints  of  a  fish  and  of  seals  had 
been  found,  and  in  Paros  the  imprint  of  an  anchovy 
at  some  depth  in  the  stone,  and  in  Melite  shallow 
impressions  of  all  sorts  of  sea  products.  He  says  that 
these  imprints  were  made  when  everything  long  ago 
was  covered  with  mud,  and  then  the  imprint  dried  in 
the  mud.  Further,  he  says  that  all  men  will  be  de- 
stroyed when  the  earth  sinks  into  the  sea  and  becomes 
mud,  and  that  the  race  will  begin  anew  from  the  be- 
ginning; and  this  transformation  takes  place  for  all 
worlds."7  Here,  then,  we  see  this  earliest  of  paleon- 
tologists studying  the  fossil-bearing  strata  of  the  earth, 
and  drawing  from  his  observations  a  marvellously 
scientific  induction.  Almost  two  thousand  years  later 
another  famous  citizen  of  Italy,  Leonardo  da  Vinci, 
was  independently  to  think  out  similar  conclusions 
from  like  observations.  But  not  until  the  nineteenth 
century  of  our  era,  some  twenty-four  hundred  years 
after  the  time  of  Xenophanes,  was  the  old  Greek's 
doctrine  to  be  accepted  by  the  scientific  world.  The 
ideas  of  Xenophanes  were  known  to  his  contempora- 
ries and,  as  we  see,  quoted  for  a  few  centuries  by  his 
successors,  then  they  were  ignored  or  quite  forgotten; 
and  if  any  philosopher  of  an  ensuing  age  before  the 
time  of  Leonardo  championed  a  like  rational  explana- 
tion of  the  fossils,  we  have  no  record  of  the  fact.  The 
geological  doctrine  of  Xenophanes,  then,  must  be  listed 
among  those  remarkable  Greek  anticipations  of  nine- 
teenth-century science  which  suffered  almost  total 
eclipse  in  the  intervening  centuries. 

Among  the  pupils  of  Xenophanes  was  Parmenides, 

VOL.   I. — 9  129 


A    HISTORY   OF   SCIENCE 

the  thinker  who  was  destined  to  carry  on  the  work  of 
his  master  along  the  same  scientific  lines,  though  at 
the  same  time  mingling  his  scientific  conceptions  with 
the  mysticism  of  the  poet.  We  have  already  had  oc- 
casion to  mention  that  Parmenides  championed  the 
idea  that  the  earth  is  round;  noting  also  that  doubts 
exist  as  to  whether  he  or  Pythagoras  originated  this 
doctrine.  No  explicit  answer  to  this  question  can 
possibly  be  hoped  for.  It  seems  clear,  however,  that 
for  a  long  time  the  Italic  School,  to  which  both  these 
philosophers  belonged,  had  a  monopoly  of  the  belief 
in  question.  Parmenides,  like  Pythagoras,  is  credited 
with  having  believed  in  the  motion  of  the  earth, 
though  the  evidence  furnished  by  the  writings  of  the 
philosopher  himself  is  not  as  demonstrative  as  one 
could  wish.  Unfortunately,  the  copyists  of  a  later 
age  were  more  concerned  with  metaphysical  specula- 
tions than  with  more  tangible  things.  But  as  far  as 
the  fragmentary  references  to  the  ideas  of  Parmenides 
may  be  accepted,  they  do  not  support  the  idea  of  the 
earth's  motion.  Indeed,  Parmenides  is  made  to  say 
explicitly,  in  preserved  fragments,  that  "the  world  is 
immovable,  limited,  and  spheroidal  in  form."  8 

Nevertheless,  some  modern  interpreters  have  found 
an  opposite  meaning  in  Parmenides.  Thus  Ritter 
interprets  him  as  supposing  "that  the  earth  is  in  the 
centre  spherical,  and  maintained  in  rotary  motion  by 
its  equiponderance ;  around  it  lie  certain  rings,  the 
highest  composed  of  the  rare  element  fire,  the  next 
lower  a  compound  of  light  and  darkness,  and  lowest  of 
all  one  wholly  of  night,  which  probably  indicated  to 
his  mind  the  surface  of  the  earth,  the  centre  of  which 

130 


EARLY  GREEK    PHILOSOPHERS    IN  ITALY 

again  he  probably  considered  to  be  fire."  9  But  this, 
like  too  many  interpretations  of  ancient  thought, 
appears  to  read  into  the  fragments  ideas  which  the 
words  themselves  do  not  warrant.  There  seems  no 
reason  to  doubt,  however,  that  Parmenides  actually 
held  the  doctrine  of  the  earth's  sphericity.  Another 
glimpse  of  his  astronomical  doctrines  is  furnished  us 
by  a  fragment  which  tells  us  that  he  conceived  the 
morning  and  the  evening  stars  to  be  the  same,  a  doc- 
trine which,  as  we  have  seen,  was  ascribed  also  to 
Pythagoras.  Indeed,  we  may  repeat  that  it  is  quite 
impossible  to  distinguish  between  the  astronomical 
doctrines  of  these  two  philosophers. 

The  poem  of  Parmenides  in  which  the  cosmogonic 
speculations  occur  treats  also  of  the  origin  of  man. 
The  author  seems  to  have  had  a  clear  conception  that 
intelligence  depends  on  bodily  organism,  and  that  the 
more  elaborately  developed  the  organism  the  higher 
the  intelligence.  But  in  the  interpretation  of  this 
thought  we  are  hampered  by  the  characteristic  vague- 
ness of  expression,  which  may  best  be  evidenced  by 
putting  before  the  reader  two  English  translations  of 
the  same  stanza.  Here  is  Ritter's  rendering,  as  made 
into  English  by  his  translator,  Morrison : 

"For  exactly  as  each  has  the  state  of  his  limbs  many-jointed, 
So  invariably  stands  it  with  men  in  their  mind  and  their 

reason ; 
For  the  system  of  limbs  is  that  which  thinketh  in  mankind 
Alike  in  all  and  in  each:  for  thought  is  the  fulness."10 

The  same  stanza  is  given  thus  by  George  Henry  Lewes : 

"Such  as  to  each  man  is  the  nature  of  his  many-jointed  limbs, 
Such  also  is  the  intelligence  of  each  man;  for  it  is. 

x3i 


A   HISTORY    OF   SCIENCE 

The  nature  of  limbs  (organization)  which  thinketh  in  men, 
Both  in  one  and  in  all ;  for  the  highest  degree  of  organization 
gives  the  highest  degree  of  thought."  " 

Here  it  will  be  observed  that  there  is  virtual  agree- 
ment between  the  translators  except  as  to  the  last 
clause,  but  that  clause  is  most  essential.  The  Greek 
phrase  is  to  yap  irXiov  ItrrX  v6r\ua.  Ritter,  it  will  be 
observed,  renders  this,  "for  thought  is  the  fulness." 
Lewes  paraphrases  it,  "  for  the  highest  degree  of  organ- 
ization gives  the  highest  degree  of  thought."  The 
difference  is  intentional,  since  Lewes  himself  criti- 
cises the  translation  of  Ritter.  Ritter's  translation 
is  certainly  the  more  literal,  but  the  fact  that  such 
diversity  is  possible  suggests  one  of  the  chief  ele- 
ments of  uncertainty  that  hamper  our  interpreta- 
tion of  the  thought  of  antiquity.  Unfortunately,  the 
mind  of  the  commentator  has  usually  been  directed 
towards  such  subtleties,  rather  than  towards  the  ex- 
pression of  precise  knowledge.  Hence  it  is  that  the 
philosophers  of  Greece  are  usually  thought  of  as  mere 
dreamers,  and  that  their  true  status  as  scientific  dis- 
coverers is  so  often  overlooked.  With  these  intangi- 
bilities we  have  no  present  concern  beyond  this  bare 
mention ;  for  us  it  suffices  to  gain  as  clear  an  idea  as  we 
may  of  the  really  scientific  conceptions  of  these  think- 
ers, leaving  the  subtleties  of  their  deductive  reasoning 
for  the  most  part  untouched. 

EMPEDOCLES 

The  latest  of  the  important  pre-Socratic  philosophers 
of  the  Italic  school  was  Empedocles,  who  was  born 
about  494  B-c-  and  lived  to  the  age  of  sixty.     These 

132 


EARLY  GREEK  PHILOSOPHERS  IN  ITALY 

dates  make  Empedocles  strictly  contemporary  with 
Anaxagoras,  a  fact  which  we  shall  do  well  to  bear  in 
mind  when  we  come  to  consider  the  latter' s  philosophy 
in  the  succeeding  chapter.  Like  Pythagoras,  Emped- 
ocles is  an  imposing  figure.  Indeed,  there  is  much 
of  similarity  between  the  personalities,  as  between  the 
doctrines,  of  the  two  men.  Empedocles,  like  Pythag- 
oras, was  a  physician ;  like  him  also  he  was  the  founder 
of  a  cult.  As  statesman,  prophet,  physicist,  physi- 
cian, reformer,  and  poet  he  showed  a  versatility  that, 
coupled  with  profundity,  marks  the  highest  genius. 
In  point  of  versatility  we  shall  perhaps  hardly  find 
his  equal  at  a  later  day — unless,  indeed,  an  exception 
be  made  of  Eratosthenes.  The  myths  that  have 
grown  about  the  name  of  Empedocles  show  that  he 
was  a  remarkable  personality.  He  is  said  to  have  been 
an  awe-inspiring  figure,  clothing  himself  in  Oriental 
splendor  and  moving  among  mankind  as  a  superior 
being.  Tradition  has  it  that  he  threw  himself  into  the 
crater  of  a  volcano  that  his  otherwise  unexplained 
disappearance  might  lead  his  disciples  to  believe  that 
he  had  been  miraculously  translated;  but  tradition 
goes  on  to  say  that  one  of  the  brazen  slippers  of  the 
philosopher  was  thrown  up  by  the  volcano,  thus  re- 
vealing his  subterfuge.  Another  tradition  of  far  more 
credible  aspect  asserts  that  Empedocles  retreated 
from  Italy,  returning  to  the  home  of  his  fathers  in 
Peloponnesus  to  die  there  obscurely.  It  seems  odd 
that  the  facts  regarding  the  death  of  so  great  a  man, 
at  so  comparatively  late  a  period,  should  be  obscure; 
but  this,  perhaps,  is  in  keeping  with  the  personality 
of   the  man  himself.      His   disciples  would   hesitate 

i33 


A   HISTORY   OF   SCIENCE 

to  ascribe  a  merely  natural  death  to   so  inspired  a 
prophet. 

Empedocles  appears  to  have  been  at  once  an  observer 
and  a  dreamer.  He  is  credited  with  noting  that  the 
pressure  of  air  will  sustain  the  weight  of  water  in  an 
inverted  tube;  with  divining,  without  the  possibility 
of  proof,  that  light  has  actual  motion  in  space;  and 
with  asserting  that  centrifugal  motion  must  keep  the 
heavens  from  falling.  He  is  credited  with  a  great 
sanitary  feat  in  the  draining  of  a  marsh,  and  his  knowl- 
edge of  medicine  was  held  to  be  supernatural.  Fort- 
unately, some  fragments  of  the  writings  of  Emped- 
ocles have  come  down  to  us,  enabling  us  to  judge  at 
first  hand  as  to  part  of  his  doctrines ;  while  still  more  is 
known  through  the  references  made  to  him  by  Plato, 
Aristotle,  and  other  commentators.  Empedocles  was 
a  poet  whose  verses  stood  the  test  of  criticism. 
In  this  regard  he  is  in  a  like  position  with  Par- 
menides;  but  in  neither  case  are  the  preserved  frag- 
ments sufficient  to  enable  us  fully  to  estimate  their 
author's  scientific  attainments.  Philosophical  writ- 
ings are  obscure  enough  at  the  best,  and  they  perforce 
become  doubly  so  when  expressed  in  verse.  Yet  there 
are  certain  passages  of  Empedocles  that  are  unequiv- 
ocal and  full  of  interest.  Perhaps  the  most  important 
conception  which  the  works  of  Empedocles  reveal  to 
us  is  the  denial  of  anthropomorphism  as  applied  to 
deity.  We  have  seen  how  early  the  anthropomorphic 
conception  was  developed  and  how  closely  it  was  all 
along  clung  to ;  to  shake  the  mind  free  from  it  then  was 
a  remarkable  feat,  in  accomplishing  which  Empedocles 
took  a  long  step  in  the  direction  of  rationalism.     His 

i34 


EARLY  GREEK  PHILOSOPHERS  IN  ITALY 

conception  is  paralleled  by  that  of  another  physician, 
Alcmaeon,  of  Proton,  who  contended  that  man's  ideas 
of  the  gods  amounted  to  mere  suppositions  at  the  very 
most.  A  rationalistic  or  sceptical  tendency  has  been 
the  accompaniment  of  medical  training  in  all  ages. 

The  words  in  which  Empedocles  expresses  his  con- 
ception of  deity  have  been  preserved  and  are  well 
worth  quoting:  "It  is  not  impossible,"  he  says,  "to 
draw  near  (to  god)  even  with  the  eyes  or  to  take  hold 
of  him  with  our  hands,  which  in  truth  is  the  best 
highway  of  persuasion  in  the  mind  of  man;  for  he  has 
no  human  head  fitted  to  a  body,  nor  do  two  shoots 
branch  out  from  the  trunk,  nor  has  he  feet,  nor  swift 
legs,  nor  hairy  parts,  but  he  is  sacred  and  ineffable 
mind  alone,  darting  through  the  whole  world  with 
swift  thoughts."  n 

How  far  Empedocles  carried  his  denial  of  anthropo- 
morphism is  illustrated  by  a  reference  of  Aristotle, 
who  asserts  "that  Empedocles  regards  god  as  most 
lacking  in  the  power  of  perception;  for  he  alone  does 
not  know  one  of  the  elements,  Strife  (hence) ,  of  perish- 
able things."  It  is  difficult  to  avoid  the  feeling  that 
Empedocles  here  approaches  the  modern  philosophical 
conception  that  God,  however  postulated  as  immutable, 
must  also  be  postulated  as  unconscious,  since  intelli- 
gence, as  we  know  it,  is  dependent  upon  the  transmu- 
tations of  matter.  But  to  urge  this  thought  would  be 
to  yield  to  that  philosophizing  tendency  which  has 
been  the  bane  of  interpretation  as  applied  to  the  an- 
cient thinkers. 

Considering  for  a  moment  the  more  tangible  accom- 
plishments of  Empedocles,  we  find  it  alleged  that  one 

135 


A   HISTORY    OF   SCIENCE 

of  his  "miracles"  consisted  of  the  preservation  of  a 
dead  body  without  putrefaction  for  some  weeks  after 
death.  We  may  assume  from  this  that  he  had  gained 
in  some  way  a  knowledge  of  embalming.  As  he  was 
notoriously  fond  of  experiment,  and  as  the  body  in 
question  (assuming  for  the  moment  the  authenticity 
of  the  legend)  must  have  been  preserved  without  dis- 
figurement, it  is  conceivable  even  that  he  had  hit  upon 
the  idea  of  injecting  the  arteries.  This,  of  course,  is 
pure  conjecture ;  yet  it  finds  a  certain  warrant,  both  in 
the  fact  that  the  words  of  Pythagoras  lead  us  to  be- 
lieve that  the  arteries  were  known  and  studied,  and  in 
the  fact  that  Empedocles'  own  words  reveal  him  also 
as  a  student  of  the  vascular  system.  Thus  Plutarch 
cites  Empedocles  as  believing  "  that  the  ruling  part  is 
not  in  the  head  or  in  the  breast,  but  in  the  blood; 
wherefore  in  whatever  part  of  the  body  the  more  of 
this  is  spread  in  that  part  men  excel."13  And  Em- 
pedocles' own  words,  as  preserved  by  Stobasus,  assert 
"  (the  heart)  lies  in  seas  of  blood  which  dart  in  opposite 
directions,  and  there  most  of  all  intelligence  centres  for 
men ;  for  blood  about  the  heart  is  intelligence  in  the  case 
of  man."  All  this  implies  a  really  remarkable  apprecia- 
tion of  the  dependence  of  vital  activities  upon  the  blood. 
This  correct  physiological  conception,  however,  was 
by  no  means  the  most  remarkable  of  the  ideas  to  which 
Empedocles  was  led  by  his  anatomical  studies.  His 
greatest  accomplishment  was  to  have  conceived  and 
clearly  expressed  an  idea  which  the  modern  evolution- 
ist connotes  when  he  speaks  of  homologous  parts — an 
idea  which  found  a  famous  modern  expositor  in  Goethe, 
as  we  shall  see  when  we  come  to  deal  with  eighteenth- 

136 


EARLY  GREEK  PHILOSOPHERS  IN  ITALY 

century  science.  Empedocles  expresses  the  idea  in 
these  words:  "Hair,  and  leaves,  and  thick  feathers  of 
birds,  are  the  same  thing  in  origin,  and  reptile  scales 
too  on  strong  limbs.  But  on  hedgehogs  sharp-pointed 
hair  bristles  on  their  backs."  u  That  the  idea  of  trans- 
mutation of  parts,  as  well  as  of  mere  homology,  was  in 
mind  is  evidenced  by  a  very  remarkable  sentence  in 
which  Aristotle  asserts,  "Empedocles  says  that  finger- 
nails rise  from  sinew  from  hardening."  Nor  is  this 
quite  all,  for  surely  we  find  the  germ  of  the  Lamarckian 
conception  of  evolution  through  the  transmission  of 
acquired  characters  in  the  assertion  that  "many  char- 
acteristics appear  in  animals  because  it  happened  to 
be  thus  in  their  birth,  as  that  they  have  such  a  spine 
because  they  happen  to  be  descended  from  one  that 
bent  itself  backward."  15  Aristotle,  in  quoting  this 
remark,  asserts,  with  the  dogmatism  which  charac- 
terizes the  philosophical  commentators  of  every  age, 
that  "  Empedocles  is  wrong,"  in  making  this  assertion; 
but  Lamarck,  who  lived  twenty-three  hundred  years 
after  Empedocles,  is  famous  in  the  history  of  the  doc- 
trine of  evolution  for  elaborating  this  very  idea. 

It  is  fair  to  add,  however,  that  the  dreamings  of 
Empedocles  regarding  the  origin  of  living  organisms 
led  him  to  some  conceptions  that  were  much  less  lu- 
minous. On  occasion,  Empedocles  the  poet  got  the 
better  of  Empedocles  the  scientist,  and  we  are  pre- 
sented with  a  conception  of  creation  as  grotesque  as 
that  which  delighted  the  readers  of  Paradise  Lost  at  a 
later  day.  Empedocles  assures  us  that  "many  heads 
grow  up  without  necks,  and  arms  were  wandering 
about,  necks   bereft   of   shoulders,  and   eyes  roamed 

i37 


A   HISTORY   OF   SCIENCE 

about  alone  with  no  foreheads."18  This  chaotic  con- 
dition, so  the  poet  dreamed,  led  to  the  union  of  many 
incongruous  parts,  producing  "creatures  with  double 
faces,  offspring  of  oxen  with  human  faces,  and  chil- 
dren of  men  with  oxen  heads."  But  out  of  this  chaos 
came,  finally,  we  are  led  to  infer,  a  harmonious  ag- 
gregation of  parts,  producing  ultimately  the  perfected 
organisms  that  we  see.  Unfortunately  the  preserved 
portions  of  the  writings  of  Empedocles  do  not  enlighten 
us  as  to  the  precise  way  in  which  final  evolution  was 
supposed  to  be  effected;  although  the  idea  of  endless 
experimentation  until  natural  selection  resulted  in 
survival  of  the  fittest  seems  not  far  afield  from  certain 
of  the  poetical  assertions.  Thus:  "As  divinity  was 
mingled  yet  more  with  divinity,  these  things  (the  va- 
rious members)  kept  coming  together  in  whatever  way 
each  might  chance."  Again:  "At  one  time  all  the 
limbs  which  form  the  body  united  into  one  by  love 
grew  vigorously  in  the  prime  of  life ;  but  yet  at  another 
time,  separated  by  evil  Strife,  they  wander  each  in 
different  directions  along  the  breakers  of  the  sea  of  life. 
Just  so  is  it  with  plants,  and  with  fishes  dwelling  in 
watery  halls,  and  beasts  whose  lair  is  in  the  mountains, 
and  birds  borne  on  wings."  17 

All  this  is  poetry  rather  than  science,  yet  such  imag- 
inings could  come  only  to  one  who  was  groping  towards 
what  we  moderns  should  term  an  evolutionary  con- 
ception of  the  origins  of  organic  life ;  and  however  gro- 
tesque some  of  these  expressions  may  appear,  it  must  be 
admitted  that  the  morphological  ideas  of  Empedocles, 
as  above  quoted,  give  the  Sicilian  philosopher  a  secure 
place  among  the  anticipators  of  the  modern  evolutionist. 

138 


VII 
GREEK   SCIENCE   IN   THE  EARLY  ATTIC   PERIOD 

WE  have  travelled  rather  far  in  our  study  of  Greek 
science,  and  yet  we  have  not  until  now  come  to 
Greece  itself.  And  even  now,  the  men  whose  names 
we  are  to  consider  were,  for  the  most  part,  born  in  out- 
lying portions  of  the  empire;  they  differed  from  the 
others  we  have  considered  only  in  the  fact  that  they 
were  drawn  presently  to  the  capital.  The  change  is 
due  to  a  most  interesting  sequence  of  historical  events. 
In  the  day  when  Thales  and  his  immediate  succes- 
sors taught  in  Miletus,  when  the  great  men  of  the 
Italic  school  were  in  their  prime,  there  was  no  single 
undisputed  centre  of  Greek  influence.  The  Greeks 
were  a  disorganized  company  of  petty  nations,  welded 
together  chiefly  by  unity  of  speech ;  but  now,  early  in 
the  fifth  century  b.c,  occurred  that  famous  attack  upon 
the  Western  world  by  the  Persians  under  Darius  and  his 
son  and  successor  Xerxes.  A  few  months  of  battling 
determined  the  fate  of  the  Western  world.  The  Orien- 
tals were  hurled  back;  the  glorious  memories  of  Mara- 
thon, Salamis,  and  Plataea  stimulated  the  patriotism 
and  enthusiasm  of  all  children  of  the  Greek  race.  The 
Greeks,  for  the  first  time,  occupied  the  centre  of  the 
historical  stage;  for  the  brief  interval  of  about  half  a 
century  the  different  Grecian  principalities  lived  to- 
gether in  relative  harmony.     One  city  was  recognized 

i39 


A   HISTORY   OF   SCIENCE 

as  the  metropolis  of  the  loosely  bound  empire ;  one  city 
became  the  home  of  culture  and  the  Mecca  towards 
which  all  eyes  turned ;  that  city,  of  course,  was  Athens. 
For  a  brief  time  all  roads  led  to  Athens,  as,  at  a  later 
date,  they  all  led  to  Rome.  The  waterways  which 
alone  bound  the  widely  scattered  parts  of  Hellas  into 
a  united  whole  led  out  from  Athens  and  back  to 
Athens,  as  the  spokes  of  a  wheel  to  its  hub.  Athens 
was  the  commercial  centre,  and,  largely  for  that  reason, 
it  became  the  centre  of  culture  and  intellectual  influ- 
ence also.  The  wise  men  from  the  colonies  visited  the 
metropolis,  and  the  wise  Athenians  went  out  to  the 
colonies.  Whoever  aspired  to  become  a  leader  in 
politics,  in  art,  in  literature,  or  in  philosophy,  made  his 
way  to  the  capital,  and  so,  with  almost  bewildering 
suddenness,  there  blossomed  the  civilization  of  the  age 
of  Pericles ;  the  civilization  which  produced  ^schylus, 
Sophocles,  Euripides,  Herodotus,  and  Thucydides ;  the 
civilization  which  made  possible  the  building  of  the 
Parthenon. 

ANAXAGORAS 

Sometime  during  the  early  part  of  this  golden  age 
there  came  to  Athens  a  middle-aged  man  from  Cla- 
zomenae,  who,  from  our  present  stand-point,  was  a 
more  interesting  personality  than  perhaps  any  other 
in  the  great  galaxy  of  remarkable  men  assembled  there. 
The  name  of  this  new-comer  was  Anaxagoras.  It  was 
said  in  after-time,  we  know  not  with  what  degree  of 
truth,  that  he  had  been  a  pupil  of  Anaximenes.  If  so, 
he  was  a  pupil  who  departed  far  from  the  teachings  of 
his  master.  What  we  know  for  certain  is  that  Anaxag- 
oras was  a  truly  original  thinker,  and  that  he  became  a 

140 


GREEK  SCIENCE  IN  EARLY  ATTIC  PERIOD 

close  friend — in  a  sense  the  teacher — of  Pericles  and  of 
Euripides.  Just  how  long  he  remained  at  Athens  is  not 
certain ;  but  the  time  came  when  he  had  made  himself 
in  some  way  objectionable  to  the  Athenian  populace 
through  his  teachings.  Filled  with  the  spirit  of  the  in- 
vestigator, he  could  not  accept  the  current  conceptions 
as  to  the  gods.  He  was  a  sceptic,  an  innovator. 
Such  men  are  never  welcome;  they  are  the  chief  fac- 
tors in  the  progress  of  thought,  but  they  must  look  al- 
ways to  posterity  for  recognition  of  their  worth;  from 
their  contemporaries  they  receive,  not  thanks,  but  per- 
secution. Sometimes  this  persecution  takes  one  form, 
sometimes  another;  to  the  credit  of  the  Greeks  be  it 
said,  that  with  them  it  usually  led  to  nothing  more 
severe  than  banishment.  In  the  case  of  Anaxagoras, 
it  is  alleged  that  the  sentence  pronounced  was  death; 
but  that,  thanks  to  the  influence  of  Pericles,  this  sen- 
tence was  commuted  to  banishment.  In  any  event, 
the  aged  philosopher  was  sent  away  from  the  city  of 
his  adoption.  He  retired  to  Lampsacus.  "It  is  not 
I  that  have  lost  the  Athenians,"  he  said;  "it  is  the 
Athenians  that  have  lost  me." 

The  exact  position  which  Anaxagoras  had  among  his 
contemporaries,  and  his  exact  place  in  the  develop- 
ment of  philosophy,  have  always  been  somewhat  in 
dispute.  It  is  not  known,  of  a  certainty,  that  he  even 
held  an  open  school  at  Athens.  Ritter  thinks  it  doubt- 
ful that  he  did.  It  was  his  fate  to  be  misunderstood, 
or  underestimated,  by  Aristotle;  that  in  itself  would 
have  sufficed  greatly  to  dim  his  fame — might,  indeed, 
have  led  to  his  almost  entire  neglect  had  he  not  been 
a  truly  remarkable  thinker.     With  most  of  the  ques- 

141 


A   HISTORY   OF   SCIENCE 

tions  that  have  exercised  the  commentators  we  have 
but  scant  concern.  Following  Aristotle,  most  histori- 
ans of  philosophy  have  been  metaphysicians ;  they  have 
concerned  themselves  far  less  with  what  the  ancient 
thinkers  really  knew  than  with  what  they  thought. 
A  chance  using  of  a  verbal  quibble,  an  esoteric  phrase, 
the  expression  of  a  vague  mysticism — these  would  suf- 
fice to  call  forth  reams  of  exposition.  It  has  been  the 
favorite  pastime  of  historians  to  weave  their  own  an- 
achronistic theories  upon  the  scanty  woof  of  the  half- 
remembered  thoughts  of  the  ancient  philosophers. 
To  make  such  cloth  of  the  imagination  as  this  is  an 
alluring  pastime,  but  one  that  must  not  divert  us  here. 
Our  point  of  view  reverses  that  of  the  philosophers. 
We  are  chiefly  concerned,  not  with  some  vague  saying 
of  Anaxagoras,  but  with  what  he  really  knew  regard- 
ing the  phenomena  of  nature;  with  what  he  observed, 
and  with  the  comprehensible  deductions  that  he  de- 
rived from  his  observations.  In  attempting  to  answer 
these  inquiries,  we  are  obliged,  in  part,  to  take  our 
evidence  at  second-hand ;  but,  fortunately,  some  frag- 
ments of  writings  of  Anaxagoras  have  come  down  to 
us.  We  are  told  that  he  wrote  only  a  single  book.  It 
was  said  even  (by  Diogenes)  that  he  was  the  first  man 
that  ever  wrote  a  work  in  prose.  The  latter  statement 
would  not  bear  too  close  an  examination,  yet  it  is  true 
that  no  extensive  prose  compositions  of  an  earlier  day 
than  this  have  been  preserved,  though  numerous 
others  are  known  by  their  fragments.  Herodotus, 
"the  father  of  prose,"  was  a  slightly  younger  contem- 
porary of  the  Clazomenaean  philosopher;  not  unlikely 
the  two  men  may  have  met  at  Athens. 

142 


GREEK  SCIENCE  IN  EARLY  ATTIC  PERIOD 

Notwithstanding  the  loss  of  the  greater  part  of  the 
writings  of  Anaxagoras,  however,  a  tolerably  precise 
account  of  his  scientific  doctrines  is  accessible.  Dioge- 
nes Laertius  expresses  some  of  them  in  very  clear  and 
precise  terms.  We  have  already  pointed  out  the  un- 
certainty that  attaches  to  such  evidence  as  this,  but  it 
is  as  valid  for  Anaxagoras  as  for  another.  If  we  reject 
such  evidence,  we  shall  often  have  almost  nothing  left ; 
in  accepting  it  we  may  at  least  feel  certain  that  we  are 
viewing  the  thinker  as  his  contemporaries  and  imme- 
diate successors  viewed  him.  Following  Diogenes, 
then,  we  shall  find  some  remarkable  scientific  opinions 
ascribed  to  Anaxagoras.  "He  asserted,"  we  are  told, 
"  that  the  sun  was  a  mass  of  burning  iron,  greater  than 
Peloponnesus^  ancL  that  the  moon  contained  houses 
and  also  hills  and  ravines."  In  corroboration  of  this, 
Plato  represents  him  as  having  conjectured  the  right 
explanation  of  the  moon's  light,  and  of  the  solar  and 
lunar  eclipses.  He  had  other  astronomical  theories 
that  were  more  fanciful;  thus  "he  said  that  the  stars 
originally  moved  about  in  irregular  confusion,  so  that 
at  first  the  pole-star,  which  is  continually  visible,  al- 
ways appeared  in  the  zenith,  but  that  afterwards  it  ac- 
quired a  certain  declination,  and  that  the  Milky  Way 
was  a  reflection  of  the  light  of  the  sun  when  the  stars 
did  not  appear.  The  comets  he  considered  to  be  a 
concourse  of  planets  emitting  rays,  and  the  shooting- 
stars  he  thought  were  sparks,  as  it  were,  leaping  from 
the  firmament." 

Much  of  this  is  far  enough  from  the  truth,  as  we  now 
know  it,  yet  all  of  it  shows  an  earnest  endeavor  to  ex- 
plain the  observed  phenomena  of  the  heavens  on  ra- 

143 


A    HISTORY    OF   SCIENCE 

tional  principles.  To  have  predicated  the  sun  as  a 
great  molten  mass  of  iron  was  indeed  a  wonderful 
anticipation  of  the  results  of  the  modern  spectroscope. 
Nor  can  it  be  said  that  this  hypothesis  of  Anaxagoras 
was  a  purely  visionary  guess.  It  was  in  all  probability 
a  scientific  deduction  from  the  observed  character  of 
meteoric  stones.  Reference  has  already  been  made 
to  the  alleged  prediction  of  the  fall  of  the  famous 
meteor  at  ^Egespotomi  by  Anaxagoras.  The  assertion 
that  he  actually  predicted  this  fall  in  any  proper  sense 
of  the  word  would  be  obviously  absurd.  Yet  the  fact 
that  his  name  is  associated  with  it  suggests  that  he  had 
studied  similar  meteorites,  or  else  that  he  studied  this 
particular  one,  since  it  is  not  quite  clear  whether  it 
was  before  or  after  this  fall  that  he  made  the  famous 
assertion  that  space  is  full  of  falling  stones.  We  should 
stretch  the  probabilities  were  we  to  assert  that  An- 
axagoras knew  that  shooting-stars  and  meteors  were 
the  same,  yet  there  is  an  interesting  suggestiveness 
in  his  likening  the  shooting-stars  to  sparks  leaping 
from  the  firmament,  taken  in  connection  with  his  ob- 
servation on  meteorites.  Be  this  as  it  may,  the  fact 
that  something  which  falls  from  heaven  as  a  blazing 
light  turns  out  to  be  an  iron-like  mass  may  very  well 
have  suggested  to  the  most  rational  of  thinkers  that 
the  great  blazing  light  called  the  sun  has  the  same 
composition.  This  idea  grasped,  it  was  a  not  un- 
natural extension  to  conceive  the  other  heavenly  bod- 
ies as  having  the  same  composition. 

This  led  to  a  truly  startling  thought.  Since  the 
heavenly  bodies  are  of  the  same  composition  as  the 
earth,   and   since  they  are  observed  to  be  whirling 

144 


GREEK  SCIENCE  IN  EARLY  ATTIC  PERIOD 

"  about  the  earth  in  space,  may  we  not  suppose  that  they 
were  once  a  part  of  the  earth  itself,  and  that  they 
have  been  thrown  ofiE  by  the  force  of  a  whirling  mo- 
tion? Such  was  the  conclusion  which  Anaxagoras 
reached ;  such  his  explanation  of  the __orjgin_pf_  the 
heavenly  .bodies.  It  was  a  marvellous  guess.  De- 
duct from  it  all  that  recent  science  has  shown  to  be  un- 
true;  bear  in  mind  that  the  stars  are  suns,  compared 
with  which  the  earth  is  a  mere  speck  of  dust;  recall 
that  the  sun  is  parent,  not  daughter,  of  the  earth,  and 
despite  all  these  deductions,  the  cosmogonic  guess  of 
Anaxagoras  remains,  as  it  seems  to  us,  one  of  the  most 
marvellous  feats  of  human  intelligence.  It  was  the 
first  explanation  of  the  cosmic  bodies  that  could  be 
called,  in  any  sense,  an  anticipation  of  what  the 
science  of  our  own  day  accepts  as  a  true  explanation 
of  cosmic  origins.  Moreover,  let  us  urge  again  that 
this  was  no  mere  accidental  flight  of  the  imagination; 
it  was  a  scientific  induction  based  on  the  only  data 
available ;  perhaps  it  is  not  too  much  to  say  that  it  was 
the  only  scientific  induction  which  these  data  would 
fairly  sustain.  Of  course  it  is  not  for  a  moment  to  be 
inferred  that  Anaxagoras  understood,  in  the  modern 
sense,  the  character  of  that  whirling  force  which  we 
call  centrifugal.  About  two  thousand  years  were  yet 
to  elapse  before  that  force  was  explained  as  elementary 
inertia;  and  even  that  explanation,  let  us  not  forget, 
merely  sufficed  to  push  back  the  barriers  of  mystery 
by  one  other  stage;  for  even  in  our  day  inertia  is  a 
statement  of  fact  rather  than  an  explanation. 

But  however  little  Anaxagoras  could  explain  the 
centrifugal  force  on  mechanical  principles,  the  prac- 

VOL.   I — IO  145 


A   HISTORY   OF   SCIENCE 

tical  powers  of  that  force  were  sufficiently  open  to  his 
observation.  The  mere  experiment  of  throwing  a 
stone  from  a  sling  would,  to  an  observing  mind,  be 
full  of  suggestiveness.  It  would  be  obvious  that  by- 
whirling  the  sling  about,  the  stone  which  it  held  would 
be  sustained  in  its  circling  path  about  the  hand  in 
seeming  defiance  of  the  earth's  pull,  and  after  the  stone 
had  left  the  sling,  it  could  fly  away  from  the  earth  to 
a  distance  which  the  most  casual  observation  would 
prove  to  be  proportionate  to  the  speed  of  its  flight. 
Extremely  rapid  motion,  then,  might  project  bodies 
from  the  earth's  surface  off  into  space;  a  sufficiently 
rapid  whirl  would  keep  them  there.  Anaxagoras 
conceived  that  this  was  precisely  what  had  occurred. 
His  imagination  even  carried  him  a  step  farther — to  a 
conception  of  a  slackening  of  speed,  through  which  the 
heavenly  bodies  would  lose  their  centrifugal  force, 
and,  responding  to  the  perpetual  pull  of  gravitation, 
would  fall  back  to  the  earth,  just  as  the  great  stone  at 
^gespotomi  had  been  observed  to  do. 

Here  we  would  seem  to  have  a  clear  conception  of 
the  idea  of  universal  gravitation,  and  Anaxagoras 
stands  before  us  as  the  anticipator  of  Newton.  Were 
it  not  for  one  scientific  maxim,  we  might  exalt  the  old 
Greek  above  the  greatest  of  modern  natural  philoso- 
phers; but  that  maxim  bids  us  pause.  It  is  phrased 
thus,  "He  discovers  who  proves."  Anaxagoras  could 
not  prove;  his  argument  was  at  best  suggestive,  not 
demonstrative.  He  did  not  even  know  the  laws 
which  govern  falling  bodies ;  much  less  could  he  apply 
such  laws,  even  had  he  known  them,  to  sidereal  bodies 
at  whose  size  and  distance  he  could  only  guess  in  the 

146 


GREEK  SCIENCE  IN  EARLY  ATTIC  PERIOD 

vaguest  terms.  Still  his  cosmogonic  speculation  re- 
mains as  perhaps  the  most  remarkable  one  of  an- 
tiquity. How  widely  his  speculation  found  currency 
among  his  immediate  successors  is  instanced  in  a 
passage  from  Plato,  where  Socrates  is  represented  as 
scornfully  answering  a  calumniator  in  these  terms: 
"He  asserts  that  I  say  the  sun  is  a  stone  and  the 
moon  an  earth.  Do  you  think  of  accusing  Anaxag- 
oras,  Miletas,  and  have  you  so  low  an  opinion  of  these 
men,  and  think  them  so  unskilled  in  laws,  as  not  to 
know  that  the  books  of  Anaxagoras  the  Clazomenasan 
are  full  of  these  doctrines.  And  forsooth  the  young 
men  are  learning  these  matters  from  me  which  some- 
times they  can  buy  from  the  orchestra  for  a  drachma, 
at  the  most,  and  laugh  at  Socrates  if  he  pretends  they 
are  his — particularly  seeing  they  are  so  strange." 

The  element  of  error  contained  in  these  cosmogonic 
speculations  of  Anaxagoras  has  led  critics  to  do  them 
something  less  than  justice.  But  there  is  one  other 
astronomical  speculation  for  which  the  Clazomenasan 
philosopher  has  received  full  credit.  It  is  generally 
admitted  that  it  was  he  who  first  found  out  the  ex- 
planation of  the  phases  of  the  moon ;  a  knowledge  that 
that  body  shines  only  by  reflected  light,  and  that  its 
visible  forms,  waxing  and  waning  month  by  month 
from  crescent  to  disk  and  from  disk  to  crescent,  merely 
represent  our  shifting  view  of  its  sun-illumined  face. 
It  is  difficult  to  put  ourselves  in  the  place  of  the  an- 
cient observer  and  realize  how  little  the  appearances 
suggest  the  actual  fact.  That  a  body  of  the  same 
structure  as  the  earth  should  shine  with  the  radiance 
of  the  moon  merely  because  sunlight  is  reflected  from 

i47 


A   HISTORY    OF   SCIENCE 

it,  is  in  itself  a  supposition  seemingly  contradicted  by 
ordinary  experience.  It  required  the  mind  of  a  phi- 
losopher, sustained,  perhaps,  by  some  experimental  ob- 
servations, to  conceive  the  idea  that  what  seems  so 
obviously  bright  may  be  in  reality  dark.  The  germ 
of  the  conception  of  what  the  philosopher  speaks  of 
as  the  noumena,  or  actualities,  back  of  phenomena 
or  appearances,  had  perhaps  this  crude  beginning. 
Anaxagoras  could  surely  point  to  the  moon  in  support 
of  his  seeming  paradox  that  snow,  being  really  com- 
posed of  water,  which  is  dark,  is  in  reality  black  and 
not  white — a  contention  to  which  we  shall  refer  more 
at  length  in  a  moment. 

But  there  is  yet  another  striking  thought  connected 
with  this  new  explanation  of  the  phases  of  the  moon. 
The  explanation  implies  not  merely  the  reflection  of 
light  by  a  dark  body,  but  by  a  dark  body  of  a  particu- 
lar form.  Granted  that  reflections  are  in  question, 
no  body  but  a  spherical  one  could  give  an  appear- 
ance which  the  moon  presents.  The  moon,  then,  is 
not  merely  a  mass  of  earth,  it  is  a  spherical  mass 
of  earth.  Here  there  were  no  flaws  in  the  reasoning 
of  Anaxagoras.  By  scientific  induction  he  passed 
from  observation  to  explanation.  A  new  and  most 
important  element  was  added  to  the  science  of  as- 
tronomy. 

Looking  back  from  the  latter-day  stand-point,  it 
would  seem  as  if  the  mind  of  the  philosopher  must 
have  taken  one  other  step:  the  mind  that  had  con- 
ceived sun,  moon,  stars,  and  earth  to  be  of  one  sub- 
stance might  naturally,  we  should  think,  have  reached 
out  to  the  further  induction  that,  since  the  moon  is  a 

148 


^REEK  SCIENCE  IN  EARLY  ATTIC  PERIOD 

sphere,  the  other  cosmic  bodies,  including  the  earth, 
must  be  spheres  also.  But  generalizer  as  he  was,  An- 
axagoras  was  too  rigidly  scientific  a  thinker  to  make 
this  assumption.  The  data  at  his  command  did  not, 
as  he  analyzed  them,  seem  to  point  to  this  conclusion. 
We  have  seen  that  Pythagoras  probably,  and  Par- 
menides  surely,  out  there  in  Italy  had  conceived  the 
idea  of  the  earth's  rotundity,  but  the  Pythagorean 
doctrines  were  not  rapidly  taken  up  in  the  mother- 
country,  and  Parmenides,  it  must  be  recalled,  was  a 
strict  contemporary  of  Anaxagoras  himself.  It  is  no 
reproach,  therefore,  to  the  Clazomenaean  philosopher 
that  he  should  have  held  to  the  old  idea  that  the 
earth  is  flat,  or  at  most  a  convex  disk — the  latter  be- 
ing the  Babylonian  conception  which  probably  domi- 
nated that  Milesian  school  to  which  Anaxagoras  harked 
back. 

Anaxagoras  may  never  have  seen  an  eclipse  of  the 
moon,  and  even  if  he  had  he  might  have  reflected  that, 
from  certain  directions,  a  disk  may  throw  precisely  the 
same  shadow  as  a  sphere.  Moreover,  in  reference  to 
the  shadow  cast  by  the  earth,  there  was,  so  Anaxagoras 
believed,  an  observation  open  to  him  nightly  which, 
we  may  well  suppose,  was  not  without  influence  in 
suggesting  to  his  mind  the  probable  shape  of  the  earth. 
The  Milky  Way,  which  doubtless  had  puzzled  astron- 
omers from  the  beginnings  of  history  and  which  was 
to  continue  to  puzzle  them  for  many  centuries  after 
the  day  of  Anaxagoras,  was  explained  by  the  Clazo- 
menaean philosopher  on  a  theory  obviously  suggested 
by  the  theory  of  the  moon's  phases.  Since  the  earth- 
like  moon   shines   by   reflected   light   at   night,    and 

149 


A   HISTORY   OF  SCIENCE 

since  the  stars  seem  obviously  brighter  on  dark  nights, 
Anaxagoras  was  but  following  up  a  perfectly  logical 
induction  when  he  propounded  the  theory  that  the 
stars  in  the  Milky  Way  seem  more  numerous  and 
brighter  than  those  of  any  other  part  of  the  heavens, 
merely  because  the  Milky  Way  marks  the  shadow  of 
the  earth.  Of  course  the  inference  was  wrong,  so  far 
as  the  shadow  of  the  earth  is  concerned ;  yet  it  contained 
a  part  truth,  the  force  of  which  was  never  fully  recog- 
nized until  the  time  of  Galileo.  This  consists  in  the 
assertion  that  the  brightness  of  the  Milky  Way  is 
merely  due  to  the  glow  of  many  stars.  The  shadow- 
theory  of  Anaxagoras  would  naturally  cease  to  have 
validity  so  soon  as  the  sphericity  of  the  earth  was 
proved,  and  with  it,  seemingly,  fell  for  the  time  the 
companion  theory  that  the  Milky  Way  is  made  up  of 
a  multitude  of  stars. 

It  has  been  said  by  a  modern  critic *  that  the 
shadow-theory  was  childish  in  that  it  failed  to  note 
that  the  Milky  Way  does  not  follow  the  course  of  the 
ecliptic.  But  this  criticism  only  holds  good  so  long 
as  we  reflect  on  the  true  character  of  the  earth  as  a 
symmetrical  body  poised  in  space.  It  is  quite  pos- 
sible to  conceive  a  body  occupying  the  position  of  the 
earth  with  reference  to  the  sun  which  would  cast  a 
shadow  having  such  a  tenuous  form  as  the  Milky  Way 
presents.  Such  a  body  obviously  would  not  be  a 
globe,  but  a  long-drawn-out,  attenuated  figure.  There 
is,  to  be  sure,  no  direct  evidence  preserved  to  show  that 
Anaxagoras  conceived  the  world  to  present  such  a 
figure  as  this,  but  what  we  know  of  that  philosopher's 
close-reasoning,  logical  mind  gives  some  warrant  to 

15° 


GREEK  SCIENCE  IN  EARLY  ATTIC  PERIOD 

the  assumption — gratuitous  though  in  a  sense  it  be — 
that  the  author  of  the  theory  of  the  moon's  phases  had 
not  failed  to  ask  himself  what  must  be  the  form  of  that 
terrestrial  body  which  could  cast  the  tenuous  shadow 
of  the  Milky  Way.  Moreover,  we  must  recall  that  the 
habitable  earth,  as  known  to  the  Greeks  of  that  day, 
was  a  relatively  narrow  band  of  territory,  stretching 
far  to  the  east  and  to  the  west. 

Anaxagoras  as  Meteorologist 

The  man  who  had  studied  the  meteorite  of  ^Egos- 
potami,  and  been  put  by  it  on  the  track  of  such  re- 
markable inductions,  was,  naturally,  not  oblivious  to 
the  other  phenomena  of  the  atmosphere.  Indeed,  such 
a  mind  as  that  of  Anaxagoras  was  sure  to  investi- 
gate all  manner  of  natural  phenomena,  and  almost 
equally  sure  to  throw  new  light  on  any  subject  that  it 
investigated.  Hence  it  is  not  surprising  to  find  Anax- 
agoras credited  with  explaining  the  winds  as  due  to  the 
rarefactions  of  the  atmosphere  produced  by  the  sun. 
This  explanation  gives  Anaxagoras  full  right  to  be 
called  ''the  father  of  meteorology,"  a  title  which,  it 
may  be,  no  one  has  thought  of  applying  to  him,  chiefly 
because  the  science  of  meteorology  did  not  make  its 
real  beginnings  until  some  twenty-four  hundred  years 
after  the  death  of  its  first  great  votary.  Not  content 
with  explaining  the  winds,  this  prototype  of  Franklin 
turned  his  attention  even  to  the  upper  atmosphere. 
"Thunder,"  he  is  reputed  to  have  said,  "was  produced 
by  the  collision  of  the  clouds,  and  lightning  by  the  rub- 
bing together  of  the  clouds."  We  dare  not  go  so  far 
as  to  suggest  that  this  implies  an  association  in  the 

I51 


A   HISTORY   OF   SCIENCE 

mind  of  Anaxagoras  between  the  friction  of  the  clouds 
and  the  observed  electrical  effects  generated  by  the 
friction  of  such  a  substance  as  amber.  To  make  such 
a  suggestion  doubtless  would  be  to  fall  victim  to  the 
old  familiar  propensity  to  read  into  Homer  things  that 
Homer  never  knew.  Yet  the  significant  fact  remains 
that  Anaxagoras  ascribed  to  thunder  and  to  lightning 
their  true  position  as  strictly  natural  phenomena. 
For  him  it  was  no  god  that  menaced  humanity  with 
thundering  voice  and  the  flash  of  his  divine  fires  from 
the  clouds.  Little  wonder  that  the  thinker  whose 
science  carried  him  to  such  scepticism  as  this  should 
have  felt  the  wrath  of  the  superstitious  Athenians. 

Biological  Speculations 

Passing  from  the  phenomena  of  the  air  to  those  of 
the  earth  itself,  we  learn  that  Anaxagoras  explained  an 
earthquake  as  being  produced  by  the  returning  of  air 
into  the  earth.  We  cannot  be  sure  as  to  the  exact 
meaning  here,  though  the  idea  that  gases  are  im- 
prisoned in  the  substance  of  the  earth  seems  not  far 
afield.  But  a  far  more  remarkable  insight  than  this 
would  imply  was  shown  by  Anaxagoras  when  he  as- 
serted that  a  certain  amount  of  air  is  contained  in 
water,  and  that  fishes  breathe  this  air.  The  pas- 
sage of  Aristotle  in  which  this  opinion  is  ascribed  to 
Anaxagoras  is  of  sufficient  interest  to  be  quoted  at 
length : 

"  Democritus,  of  Abdera,"  says  Aristotle,  "and  some 
others,  that  have  spoken  concerning  respiration,  have 
determined  nothing  concerning  other  animals,  but 
seem  to  have  supposed  that  all  animals  respire.     But 

152 


GREEK  SCIENCE  IN  EARLY  ATTIC  PERIOD 

Anaxagoras  and  Diogenes  (Apolloniates) ,  who  say  that 
all  animals  respire,  have  also  endeavored  to  explain 
how  fishes,  and  all  those  animals  that  have  a  hard, 
rough  shell,  such  as  oysters,  mussels,  etc.,  respire. 
And  Anaxagoras,  indeed,  says  that  fishes,  when  they 
emit  water  through  their  gills,  attract  air  from  the 
mouth  to  the  vacuum  in  the  viscera  from  the  water 
which  surrounds  the  mouth ;  as  if  air  was  inherent  in 
the  water."  2 

It  should  be  recalled  that  of  the  three  philosophers 
thus  mentioned  as  contending  that  all  animals  re- 
spire, Anaxagoras  was  the  elder;  he,  therefore,  was 
presumably  the  originator  of  the  idea.  It  will  be 
observed,  too,  that  Anaxagoras  alone  is  held  respon- 
sible for  the  idea  that  fishes  respire  air  through  their 
gills,  "attracting"  it  from  the  water.  This  certainly 
was  one  of  the  shrewdest  physiological  guesses  of 
any  age,  if  it  be  regarded  as  a  mere  guess.  With 
greater  justice  we  might  refer  to  it  as  a  profound 
deduction  from  the  principle  of  the  uniformity  of 
nature. 

In  making  such  a  deduction,  Anaxagoras  was  far  in 
advance  of  his  time  as  illustrated  by  the  fact  that 
Aristotle  makes  the  citation  we  have  just  quoted 
merely  to  add  that  "such  things  are  impossible,"  and 
to  refute  these  "impossible"  ideas  by  means  of  meta- 
physical reasonings  that  seemed  demonstrative  not 
merely  to  himself,  but  to  many  generations  of  his  fol- 
lowers. 

We  are  told  that  Anaxagoras  alleged  that  all  animals 
were  originally  generated  out  of  moisture,  heat,  and """- 
earth  particles.     Just  what  opinion  he  held  concerning 

153 


A   HISTORY   OF  SCIENCE 

man's  development  we  are  not  informed.  Yet  there  is 
one  of  his  phrases  which  suggests — without,  perhaps, 
quite  proving  —  that  he  was  an  evolutionist.  This 
phrase  asserts,  with  insight  that  is  fairly  startling, 
that  man  is  the  most  intelligent  of  animals  because  he 
has  hands.  The  man  who  could  make  that  assertion 
must,  it  would  seem,  have  had  in  mind  the  idea  of  the 
development  of  intelligence  through  the  use  of  hands— 
an  idea  the  full  force  of  which  was  not  evident  to 
subsequent  generations  of  thinkers  until  the  time  of 
Darwin. 

Physical  Speculations 

Anaxagoras  is  cited  by  Aristotle  as  believing  that 
"plants  are  animals  and  feel  pleasure  and  pain,  in- 
ferring this  because  they  shed  their  leaves  and  let 
them  grow  again."  The  idea  is  fanciful,  yet  it  suggests 
again  a  truly  philosophical  conception  of  the  unity  of 
nature.  The  man  who  could  conceive  that  idea  was 
but  little  hampered  by  traditional  conceptions.  He 
was  exercising  a  rare  combination  of  the  rigidly  scien- 
tific spirit  with  the  poetical  imagination.  He  who 
possesses  these  gifts  is  sure  not  to  stop  in  his  ques- 
tionings of  nature  until  he  has  found  some  thinkable 
explanation  of  the  character  of  matter  itself.  Anax- 
agoras found  such  an  explanation,  and,  as  good  luck 
would  have  it,  that  explanation  has  been  preserved. 
Let  us  examine  his  reasoning  in  some  detail.  We 
have  already  referred  to  the  claim  alleged  to  have  been 
made  by  Anaxagoras  that  snow  is  not  really  white, 
but  black.  The  philosopher  explained  his  paradox, 
we  are  told,  by  asserting  that  snow  is  really  water, 

i54 


GREEK  SCIENCE  IN  EARLY  ATTIC  PERIOD 

and  that  water  is  dark,  when  viewed  under  proper 
conditions — as  at  the  bottom  of  a  well.  That  idea 
contains  the  germ  of  the  Clazomenasan  philosopher's 
conception  of  the  nature  of  matter.  Indeed,  it  is  not 
unlikely  that  this  theory  of  matter  grew  out  of  his 
observation  of  the  changing  forms  of  water.  He  seems 
clearly  to  have  grasped  the  idea  that  snow  on  the  one 
hand,  and  vapor  on  the  other,  are  of  the  same  in- 
timate substance  as  the  water  from  which  they  are 
derived  and  into  which  they  may  be  again  transformed. 
The  fact  that  steam  and  snow  can  be  changed  back 
into  water,  and  by  simple  manipulation  cannot  be 
changed  into  any  other  substance,  finds,  as  we  now  be- 
lieve, its  true  explanation  in  the  fact  that  the  molecular 
structure,  as  we  phrase  it — that  is  to  say,  the  ultimate 
particle  of  which  water  is  composed,  is  not  changed, 
and  this  is  precisely  the  explanation  which  Anaxagoras 
gave  of  the  same  phenomena.  For  him  the  unit  par- 
ticle of  water  constituted  an  elementary  body,  un- 
created, unchangeable,  indestructible.  This  particle, 
in  association  with  like  particles,  constitutes  the  sub- 
stance which  we  call  water.  The  same  particle  in 
association  with  particles  unlike  itself,  might  produce 
totally  different  substances  —  as,  for  example,  when 
water  is  taken  up  by  the  roots  of  a  plant  and  becomes, 
seemingly,  a  part  of  the  substance  of  the  plant.  But 
whatever  the  changed  association,  so  Anaxagoras 
reasoned,  the  ultimate  particle  of  water  remains  a  par- 
ticle of  water  still.  And  what  was  true  of  water  was 
true  also,  so  he  conceived,  of  every  other  substance. 
Gold,  silver,  iron,  earth,  and  the  various  vegetables 
and  animal  tissues — in  short,  each  and  every  one  of 

MA'    I55 


A   HISTORY   OF   SCIENCE 

all  the  different  substances  with  which  experience 
makes  us  familiar,  is  made  up  of  unit  particles  which 
maintain  their  integrity  in  whatever  combination 
they  may  be  associated.  This  implies,  obviously,  a 
multitude  of  primordial  particles,  each  one  having  an 
individuality  of  its  own;  each  one,  like  the  particle  of 
water  already  cited,  uncreated,  unchangeable,  and 
indestructible. 

Fortunately,  we  have  the  philosopher's  own  words 
to  guide  us  as  to  his  speculations  here.  The  frag- 
ments of  his  writings  that  have  come  down  to  us 
(chiefly  through  the  quotations  of  Simplicius)  deal 
almost  exclusively  with  these  ultimate  conceptions  of 
his  imagination.  In  ascribing  to  him,  then,  this  con- 
ception of  diverse,  uncreated,  primordial  elements, 
which  can  never  be  changed,  but  can  only  be  mixed 
together  to  form  substances  of  the  material  world, 
we  are  not  reading  back  post-Daltonian  knowledge 
into  the  system  of  Anaxagoras.  Here  are  his  words : 
"The  Greeks  do  not  rightly  use  the  terms  'coming 
into  being'  and  'perishing.'  For  nothing  comes  into 
being,  nor,  yet,  does  anything  perish;  but  there  is 
mixture  and  separation  of  things  that  are.  So  they 
would  do  right  in  calling  '  coming  into  being '  '  mixture ' 
and  'perishing'  'separation.'  For  how  could  hair 
come  from  what  is  not  hair?  Or  flesh  from  what  is 
not  flesh?" 

Elsewhere  he  tells  us  that  (at  one  stage  of  the  world's 
development)  "  the  dense,  the  moist,  the  cold,  the  dark, 
collected  there  where  now  is  earth ;  the  rare,  the  warm, 
the  dry,  the  bright,  departed  towards  the  further  part 
of  the  aether.     The  earth  is  condensed  out  of  these 

156 


GREEK  SCIENCE  IN  EARLY  ATTIC  PERIOD 

things  that  are  separated,  for  water  is  separated  from 
the  clouds,  and  earth  from  the  water;  and  from  the 
earth  stones  are  condensed  by  the  cold,  and  these  are 
separated  farther  from  the  water."  Here  again  the 
influence  of  heat  and  cold  in  determining  physical 
qualities  is  kept  pre-eminently  in  mind.  The  dense, 
the  moist,  the  cold,  the  dark  are  contrasted  with  the 
rare,  the  warm,  the  dry,  and  bright ;  and  the  formation 
i  of  stones  is  spoken  of  as  a  specific  condensation  due  to 
the  influence  of  cold.  Here,  then,  we  have  nearly  all 
the  elements  of  the  Daltonian  theory  of  atoms  on  the 
one  hand,  and  the  nebular  hypothesis  of  Laplace  on 
the  other.  But  this  is  not  quite  all.  In  addition  to 
such  diverse  elementary  particles  as  those  of  gold, 
water,  and  the  rest,  Anaxagoras  conceived  a  species 
of  particles  differing  from  all  the  others,  not  merely 
as  they  differ  from  one  another,  but  constituting  a 
class  by  themselves;  particles  infinitely  smaller  than 
the  others;  particles  that  are  described  as  infinite, 
self -powerful,  mixed  with  nothing,  but  existing  alone. 
That  is  to  say  (interpreting  the  theory  in  the  only 
way  that  seems  plausible),  these  most  minute  par- 
ticles do  not  mix  with  the  other  primordial  particles 
to  form  material  substances  in  the  same  way  in  which 
these  mixed  with  one  another.  But,  on  the  other 
hand,  these  "infinite,  self -powerful,  and  unmixed" 
particles  commingle  everywhere  and  in  every  sub- 
stance whatever  with  the  mixed  particles  that  go  to 
make  up  the  substances. 

There  is  a  distinction  here,  it  will  be  observed, 
which  at  once  suggests  the  modern  distinction  between 
physical  processes  and  chemical  processes,  or,  putting 

i57 


A   HISTORY  OF  SCIENCE 

it  otherwise,  between  molecular  processes  and  atomic 
processes ;  but  the  reader  must  be  guarded  against  sup- 
posing that  Anaxagoras  had  any  such  thought  as  this 
in  mind.  His  ultimate  mixable  particles  can  be  com- 
pared only  with  the  Daltonian  atom,  not  with  the  mol- 
ecule of  the  modern  physicist,  and  his  "infinite,  self- 
powerful,  and  unmixable ' '  particles  are  not  comparable 
with  anything  but  the  ether  of  the  modern  physicist, 
with  which  hypothetical  substance  they  have  many 
points  of  resemblance.  But  the  "infinite,  self -pow- 
erful, and  unmixed"  particles  constituting  thus  an 
ether-like  plenum  which  permeates  all  material  struct- 
ures, have  also,  in  the  mind  of  Anaxagoras,  a  function 
which  carries  them  perhaps  a  stage  beyond  the  prov- 
ince of  the  modern  ether.  For  these  "infinite,  self- 
powerful,  and  unmixed"  particles  are  imbued  with, 
and,  indeed,  themselves  constitute,  what  Anaxagoras 
terms  nous,  a  word  which  the  modern  translator  has 
usually  paraphrased  as  "mind."  Neither  that  word 
nor  any  other  available  one  probably  conveys  an  ac- 
curate idea  of  what  Anaxagoras  meant  to  imply  by  the 
word  nous.  For  him  the  word  meant  not  merely 
"mind"  in  the  sense  of  receptive  and  comprehending 
intelligence,  but  directive  and  creative  intelligence 
as  well.  Again  let  Anaxagoras  speak  for  himself: 
"Other  things  include  a  portion  of  everything,  but 
nous  is  infinite,  and  self  -  powerful,  and  mixed  with 
nothing,  but  it  exists  alone,  itself  by  itself.  For  if  it 
were  not  by  itself,  but  were  mixed  with  anything  else, 
it  would  include  parts  of  all  things,  if  it  were  mixed  with 
anything ;  for  a  portion  of  everything  exists  in  every- 
thing,  as  has  been  said  by  me  before,   and  things 

158 


GREEK  SCIENCE  IN  EARLY  ATTIC  PERIOD 

mingled  with  it  would  prevent  it  from  having  power 
over  anything  in  the  same  way  that  it  does  now  that  it 
is  alone  by  itself.  For  it  is  the  most  rarefied  of  all 
things  and  the  purest,  and  it  has  all  knowledge  in  re- 
gard to  everything  and  the  greatest  power;  over  all 
that  has  life,  both  greater  and  less,  nous  rules.  And 
nous  ruled  the  rotation  of  the  whole,  so  that  it  set  it  in 
rotation  in  the  beginning.  First  it  began  the  rotation 
from  a  small  beginning,  then  more  and  more  was  in- 
cluded in  the  motion,  and  yet  more  will  be  included. 
Both  the  mixed  and  the  separated  and  distinct,  all 
things  nous  recognized.  And  whatever  things  were 
to  be,  and  whatever  things  were,  as  many  as  are  now, 
and  whatever  things  shall  be,  all  these  nous  arranged 
in  order;  and  it  arranged  that  rotation,  according  to 
which  now  rotate  stars  and  sun  and  moon  and  air  and 
aether,  now  that  they  are  separated.  Rotation  itself 
caused  the  separation,  and  the  dense  is  separated  from 
the  rare,  the  warm  from  the  cold,  the  bright  from  the 
dark,  the  dry  from  the  moist.  And  when  nous  began 
to  set  things  in  motion,  there  was  separation  from 
everything  that  was  in  motion,  all  this  was  made  dis- 
tinct. The  rotation  of  the  things  that  were  moved 
and  made  distinct  caused  them  to  be  yet  more  dis- 
tinct." 3 

Nous,  then,  as  Anaxagoras  conceives  it,  is  "  the  most 
rarefied  of  all  things,  and  the  purest,  and  it  has  knowl- 
edge in  regard  to  everything  and  the  greatest  power; 
over  all  that  has  life,  both  greater  and  less,  it  rules." 
But  these  are  postulants  of  omnipresence  and  om- 
niscience. In  other  words,  nous  is  nothing  less  than 
the  omnipotent  artificer  of  the  material  universe.     It 

159 


A   HISTORY    OF   SCIENCE 

lacks  nothing  of  the  power  of  deity,  save  only  that  we 
are  not  assured  that  it  created  the  primordial  particles. 
The  creation  of  these  particles  was  a  conception  that 
for  Anaxagoras,  as  for  the  modern  Spencer,  lay  beyond 
the  range  of  imagination.  Nous  is  the  artificer,  work- 
ing with  "uncreated"  particles.  Back  of  nous  and 
the  particles  lies,  for  an  Anaxagoras  as  for  a  Spencer, 
the  Unknowable.  But  nous  itself  is  the  equivalent  of 
that  universal  energy  of  motion  which  science  recog- 
nizes as  operating  between  the  particles  of  matter,  and 
which  the  theologist  personifies  as  Deity.  It  is  Pan- 
theistic deity  as  Anaxagoras  conceives  it ;  his  may  be 
called  the  first  scientific  conception  of  a  non-anthropo- 
morphic god.  In  elaborating  this  conception  Anaxag- 
oras proved  himself  one  of  the  most  remarkable  scien- 
tific dreamers  of  antiquity.  To  have  substituted  for 
the  Greek  Pantheon  of  anthropomorphic  deities  the 
conception  of  a  non-anthropomorphic  immaterial  and 
ethereal  entity,  of  all  things  in  the  world  "  the  most 
rarefied  and  the  purest,"  is  to  have  performed  a  feat 
which,  considering  the  age  and  the  environment  in 
which  it  was  accomplished,  staggers  the  imagination. 
As  a  strictly  scientific  accomplishment  the  great  think- 
er's conception  of  primordial  elements  contained  a 
germ  of  the  truth  which  was  to  lie  dormant  for  2200 
years,  but  which  then,  as  modified  and  vitalized  by 
the  genius  of  Dalton,  was  to  dominate  the  new  chemical 
science  of  the  nineteenth  century.  If  there  are  inti- 
mations that  the  primordial  element  of  Anaxagoras 
and  of  Dalton  may  turn  out  in  the  near  future  to  be 
itself  a  compound,  there  will  still  remain  the  yet  finer 
particles  of  the  nous  of  Anaxagoras  to  baffle  the  most 

160 


GREEK  SCIENCE  IN  EARLY  ATTIC  PERIOD 

subtle  analysis  of  which  to-day's  science  gives  us  any 
pre-vision.  All  in  all,  then,  the  work  of  Anaxagoras 
must  stand  as  that  of  perhaps  the  most  far-seeing 
scientific  imagination  of  pre-Socratic  antiquity. 

LEUCIPPUS    AND   DEMOCRITUS 

But  we  must  not  leave  this  alluring  field  of  specula- 
tion as  to  the  nature  of  matter  without  referring  to 
another  scientific  guess,  which  soon  followed  that  of 
Anaxagoras  and  was  destined  to  gain  even  wider  fame, 
and  which  in  modern  times  has  been  somewhat  un- 
justly held  to  eclipse  the  glory  of  the  other  achieve- 
ment. We  mean,  of  course,  the  atomic  theory  of 
Leucippus  and  Democritus.  This  theory  reduced  all 
matter  to  primordial  elements,  called  atoms  arofxa 
because  they  are  by  hypothesis  incapable  of  further 
division.  These  atoms,  making  up  the  entire  ma- 
terial universe,  are  in  this  theory  conceived  as  qual- 
itatively identical,  differing  from  one  another  only 
in  size  and  perhaps  in  shape.  The  union  of  differ- 
ent-sized atoms  in  endless  combinations  produces  the 
diverse  substances  with  which  our  senses  make  us 
familiar. 

Before  we  pass  to  a  consideration  of  this  alluring 
theory,  and  particularly  to  a  comparison  of  it  with 
the  theory  of  Anaxagoras,  we  must  catch  a  glimpse 
of  the  personality  of  the  men  to  whom  the  theory 
owes  its  origin.  One  of  these,  Leucippus,  presents 
so  uncertain  a  figure  as  to  be  almost  mythical.  In- 
deed, it  was  long  questioned  whether  such  a  man 
had  actually  lived,  or  whether  he  were  not  really  an 
invention  of  his  alleged  disciple,  Democritus.     Latter- 

VOL.    I. — II  l6l 


A   HISTORY   OF   SCIENCE 

day  scholarship,  however,  accepts  him  as  a  real  per- 
sonage, though  knowing  scarcely  more  of  him  than 
that  he  was  the  author  of  the  famous  theory  with 
which  his  name  was  associated.  It  is  suggested  that 
he  was  a  wanderer,  like  most  philosophers  of  his 
time,  and  that  later  in  life  he  came  to  Abdera,  in 
Thrace,  and  through  this  circumstance  became  the 
teacher  of  Democritus.  This  fable  answers  as  well 
as  another.  What  we  really  know  is  that  Democ- 
ritus himself,  through  whose  writings  and  teachings 
the  atomic  theory  gained  vogue,  was  born  in  Abdera, 
about  the  year  460  b.c. — that  is  to  say,  just  about 
the  time  when  his  great  precursor,  Anaxagoras,  was 
migrating  to  Athens.  Democritus,  like  most  others 
of  the  early  Greek  thinkers,  lives  in  tradition  as  a  pict- 
uresque figure.  It  is  vaguely  reported  that  he  trav- 
elled for  a  time,  perhaps  in  the  East  and  in  Egypt,  and 
that  then  he  settled  down  to  spend  the  remainder  of  his 
life  in  Abdera.  Whether  or  not  he  visited  Athens  in 
the  course  of  his  wanderings  we  do  not  know.  At 
Abdera  he  was  revered  as  a  sage,  but  his  influence  upon 
the  practical  civilization  of  the  time  was  not  marked. 
He  was  pre-eminently  a  dreamer  and  a  writer.  Like 
his  confreres  of  the  epoch,  he  entered  all  fields  of 
thought.  He  wrote  voluminously,  but,  unfortunately, 
his  writings  have,  for  the  most  part,  perished.  The 
fables  and  traditions  of  a  later  day  asserted  that  De- 
mocritus had  voluntarily  put  out  his  own  eyes  that  he 
might  turn  his  thoughts  inward  with  more  concentra- 
tion. Doubtless  this  is  fiction,  yet,  as  usual  with 
such  fictions,  it  contains  a  germ  of  truth;  for  we  may 
well  suppose   that   the   promulgator  of   the   atomic 

162 


GREEK  SCIENCE  IN  EARLY  ATTIC  PERIOD 

theory  was  a  man  whose  mind  was  attracted  by  the 
subtleties  of  thought  rather  than  by  the  tangibilities 
of  observation.  Yet  the  term  "  laughing  philosopher," 
which  seems  to  have  been  universally  applied  to  De- 
mocritus,  suggests  a  mind  not  altogether  withdrawn 
from  the  world  of  practicalities. 

So  much  for  Democritus  the  man.  Let  us  return 
now  to  his  theory  of  atoms.  This  theory,  it  must  be 
confessed,  made  no  very  great  impression  upon  his 
contemporaries.  It  found  an  expositor,  a  little  later, 
in  the  philosopher  Epicurus,  and  later  still  the  poet 
Lucretius  gave  it  popular  expression.  But  it  seemed 
scarcely  more  than  the  dream  of  a  philosopher  or  the 
vagary  of  a  poet  until  the  day  when  modern  science 
began  to  penetrate  the  mysteries  of  matter.  When, 
finally,  the  researches  of  Dalton  and  his  followers  had 
placed  the  atomic  theory  on  a  surer  footing  as  the  foun- 
dation of  modern  chemistry,  the  ideas  of  the  old  laugh- 
ing philosopher  of  Abdera,  which  all  along  had  been  half 
derisively  remembered,  were  recalled  with  a  new  inter- 
est. Now  it  appeared  that  these  ideas  had  curiously 
foreshadowed  nineteenth-century  knowledge.  It  ap- 
peared that  away  back  in  the  fifth  century  B.C.  a  man 
had  dreamed  out  a  conception  of  the  ultimate  nature 
of  matter  which  had  waited  all  these  centuries  for  cor- 
roboration. And  now  the  historians  of  philosophy  be- 
came more  than  anxious  to  do  justice  to  the  memory 
of  Democritus. 

It  is  possible  that  this  effort  at  poetical  restitution 
has  carried  the  enthusiast  too  far.  There  is,  indeed,  a 
curious  suggestiveness  in  the  theory  of  Democritus; 
there  is  philosophical  allurement  in  his  reduction  of  all 

163 


A   HISTORY   OF   SCIENCE 

matter  to  a  single  element ;  it  contains,  it  may  be,  not 
merely  a  germ  of  the  science  of  the  nineteenth-century 
chemistry,  but  perhaps  the  germs  also  of  the  yet  un- 
developed chemistry  of  the  twentieth  century.  Yet 
we  dare  suggest  that  in  their  enthusiasm  for  the  atomic 
theory  of  Democritus  the  historians  of  our  genera- 
tion have  done  something  less  than  justice  to  that 
philosopher's  precursor,  Anaxagoras.  And  one  sus- 
pects that  the  mere  accident  of  a  name  has  been 
instrumental  in  producing  this  result.  Democritus 
called  his  primordial  element  an  atom;  Anaxagoras, 
too,  conceived  a  primordial  element,  but  he  called  it 
merely  a  seed  or  thing ;  he  failed  to  christen  it  distinc- 
tively. Modern  science  adopted  the  word  atom  and 
gave  it  universal  vogue.  It  owed  a  debt  of  gratitude 
to  Democritus  for  supplying  it  the  word,  but  it  some- 
what overpaid  the  debt  in  too  closely  linking  the  new 
meaning  of  the  word  with  its  old  original  one.  For, 
let  it  be  clearly  understood,  the  Daltonian  atom  is  not 
precisely  comparable  with  the  atom  of  Democritus. 
The  atom,  as  Democritus  conceived  it,  was  monis- 
tic; all  atoms,  according  to  this  hypothesis,  are  of 
the  same  substance;  one  atom  differs  from  another 
merely  in  size  and  shape,  but  not  at  all  in  quality. 
But  the  Daltonian  hypothesis  conceived,  and  nearly 
all  the  experimental  efforts  of  the  nineteenth  century 
seemed  to  prove,  that  there  are  numerous  classes  of 
atoms,  each  differing  in  its  very  essence  from  the 
others. 

As  the  case  stands  to-day  the  chemist  deals  with 
seventy  -  odd  substances,  which  he  calls  elements. 
Each  one  of  these  substances  is,  as  he  conceives  it, 

164 


GREEK  SCIENCE  IN  EARLY  ATTIC  PERIOD 

made  up  of  elementary  atoms  having  a  unique  person- 
ality, each  differing  in  quality  from  all  the  others. 
As  far  as  experiment  has  thus  far  safely  carried  us,  the 
atom  of  gold  is  a  primordial  element  which  remains  an 
atom  of  gold  and  nothing  else,  no  matter  with  what 
other  atoms  it  is  associated.  So,  too,  of  the  atom 
of  silver,  or  zinc,  or  sodium  —  in  short,  of  each  and 
every  one  of  the  seventy-odd  elements.  There  are,  in- 
deed, as  we  shall  see,  experiments  that  suggest  the 
dissolution  of  the  atom — that  suggest,  in  short,  that  the 
Daltonian  atom  is  misnamed,  being  a  structure  that 
may,  under  certain  conditions,  be  broken  asunder. 
But  these  experiments  have,  as  yet,  the  warrant  rather 
of  philosophy  than  of  pure  science,  and  to-day  we  de- 
mand that  the  philosophy  of  science  shall  be  the  hand- 
maid of  experiment. 

When  experiment  shall  have  demonstrated  that  the 
Daltonian  atom  is  a  compound,  and  that  in  truth  there 
is  but  a  single  true  atom,  which,  combining  with  its 
fellows  perhaps  in  varying  numbers  and  in  different 
special  relations,  produces  the  Daltonian  atoms,  then 
the  philosophical  theory  of  monism  will  have  the  experi- 
mental warrant  which  to-day  it  lacks ;  then  we  shall  be 
a  step  nearer  to  the  atom  of  Democritus  in  one  direc- 
tion, a  step  farther  away  in  the  other.  We  shall  be 
nearer,  in  that  the  conception  of  Democritus  was,  in  a 
sense,  monistic ;  farther  away,  in  that  all  the  atoms  of 
Democritus,  large  and  small  alike,  were  considered  as 
permanently  fixed  in  size.  Democritus  postulated 
all  his  atoms  as  of  the  same  substance,  differing  not  at 
all  in  quality;  yet  he  was  obliged  to  conceive  that  the 
varying  size  of  the  atoms  gave  to  them  varying  func- 

165 


A   HISTORY   OF   SCIENCE 

tions  which  amounted  to  qualitative  differences.  He 
might  claim  for  his  largest  atom  the  same  quality  of 
substance  as  for  his  smallest,  but  so  long  as  he  con- 
ceived that  the  large  atoms,  when  adjusted  together  to 
form  a  tangible  substance,  formed  a  substance  differ- 
ent in  quality  from  the  substance  which  the  small 
atoms  would  make  up  when  similarly  grouped,  this 
concession  amounts  to  the  predication  of  difference  of 
quality  between  the  atoms  themselves.  The  entire 
question  reduces  itself  virtually  to  a  quibble  over  the 
word  quality.  So  long  as  one  atom  conceived  to  be 
primordial  and  indivisible  is  conceded  to  be  of  such 
a  nature  as  necessarily  to  produce  a  different  impres- 
sion on  our  senses,  when  grouped  with  its  fellows, 
from  the  impression  produced  by  other  atoms  when 
similarly  grouped,  such  primordial  atoms  do  differ 
among  themselves  in  precisely  the  same  way  for  all 
practical  purposes  as  do  the  primordial  elements  of 
Anaxagoras. 

The  monistic  conception  towards  which  twentieth- 
century  chemistry  seems  to  be  carrying  us  may  per- 
haps show  that  all  the  so-called  atoms  are  compounded 
of  a  single  element.  All  the  true  atoms  making  up  that 
element  may  then  properly  be  said  to  have  the  same 
quality,  but  none  the  less  will  it  remain  true  that  the 
combinations  of  that  element  that  go  to  make  up  the 
different  Daltonian  atoms  differ  from  one  another  in 
quality  in  precisely  the  same  sense  in  which  such  tangi- 
ble substances  as  gold,  and  oxygen,  and  mercury,  and 
diamonds  differ  from  one  another.  In  the  last  analysis 
of  the  monistic  philosophy,  there  is  but  one  substance 
and  one  quality  in  the  universe.     In  the  widest  view 

166 


GREEK  SCIENCE  IN  EARLY  ATTIC   PERIOD 

of  that  philosophy,  gold  and  oxygen  and  mercury  and 
diamonds  are  one  substance,  and,  if  you  please,  one 
quality.  But  such  refinements  of  analysis  as  this  are 
for  the  transcendental  philosopher,  and  not  for  the 
scientist.  Whatever  the  allurement  of  such  reasoning, 
we  must  for  the  purpose  of  science  let  words  have  a 
specific  meaning,  nor  must  we  let  a  mere  word-jugglery 
blind  us  to  the  evidence  of  facts.  That  was  the  rock 
on  which  Greek  science  foundered ;  it  is  the  rock  which 
the  modern  helmsman  sometimes  finds  it  difficult  to 
avoid.  And  if  we  mistake  not,  this  case  of  the  atom  of 
Democritus  is  precisely  a  case  in  point.  Because  De- 
mocritus  said  that  his  atoms  did  not  differ  in  quality, 
the  modern  philosopher  has  seen  in  his  theory  the  es- 
sentials of  monism ;  has  discovered  in  it  not  merely  a 
forecast  of  the  chemistry  of  the  nineteenth  century, 
but  a  forecast  of  the  hypothetical  chemistry  of  the 
future.  And,  on  the  other  hand,  because  Anaxagoras 
predicted  a  different  quality  for  his  primordial  ele- 
ments, the  philosopher  of  our  day  has  discredited  the 
primordial  element  of  Anaxagoras. 

Yet  if  our  analysis  does  not  lead  us  astray,  the 
theory  of  Democritus  was  not  truly  monistic;  his  in- 
destructible atoms,  differing  from  one  another  in  size 
and  shape,  utterly  incapable  of  being  changed  from 
the  form  which  they  had  maintained  from  the  be- 
ginning, were  in  reality  as  truly  and  primordially  dif- 
ferent as  are  the  primordial  elements  of  Anaxagoras. 
In  other  words,  the  atom  of  Democritus  is  nothing  less 
than  the  primordial  seed  of  Anaxagoras,  a  little  more 
tangibly  visualized  and  given  a  distinctive  name. 
Anaxagoras  explicitly  conceived  his  elements  as  in- 

167 


A   HISTORY   OF   SCIENCE 

visibly  small,  as  infinite  in  number,  and  as  made  up  of 
an  indefinite  number  of  kinds — one  for  each  distinctive 
substance  in  the  world.  But  precisely  the  same  post- 
ulates are  made  of  the  atom  of  Democritus.  These 
also  are  invisibly  small;  these  also  are  infinite  in  num- 
ber; these  also  are  made  up  of  an  indefinite  number 
of  kinds,  corresponding  with  the  observed  difference 
of  substances  in  the  world.  "Primitive  seeds,"  or 
"atoms,"  were  alike  conceived  to  be  primordial,  un- 
changeable, and  indestructible.  Wherein  then  lies  the 
difference?  We  answer,  chiefly  in  a  name;  almost 
solely  in  the  fact  that  Anaxagoras  did  not  attempt  to 
postulate  the  physical  properties  of  the  elements  be- 
yond stating  that  each  has  a  distinctive  personality, 
while  Democritus  did  attempt  to  postulate  these  prop- 
erties. He,  too,  admitted  that  each  kind  of  element 
has  its  distinctive  personality,  and  he  attempted  to 
visualize  and  describe  the  characteristics  of  the  per- 
sonality. 

Thus  while  Anaxagoras  tells  us  nothing  of  his  ele- 
ments except  that  they  differ  from  one  another,  De- 
mocritus postulates  a  difference  in  size,  imagines  some 
elements  as  heavier  and  some  as  lighter,  and  conceives 
even  that  the  elements  may  be  provided  with  project- 
ing hooks,  with  the  aid  of  which  they  link  themselves 
one  with  another.  No  one  to-day  takes  these  crude 
visualizings  seriously  as  to  their  details.  The  sole  ele- 
ment of  truth  which  these  dreamings  contain,  as  dis- 
tinguishing them  from  the  dreamings  of  Anaxagoras, 
is  in  the  conception  that  the  various  atoms  differ 
in  size  and  weight.  Here,  indeed,  is  a  vague  fore- 
shadowing of  that  chemistry  of   form  which  began 

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GREEK  SCIENCE  IN  EARLY  ATTIC  PERIOD 

to  come  into  prominence  towards  the  close  of  the 
nineteenth  century.  To  have  forecast  even  dimly  this 
newest  phase  of  chemical  knowledge,  across  the  abyss 
of  centuries,  is  indeed  a  feat  to  put  Democritus  in 
the  front  rank  of  thinkers.  But  this  estimate  should 
not  blind  us  to  the  fact  that  the  pre-vision  of  De- 
mocritus was  but  a  slight  elaboration  of  a  theory 
which  had  its  origin  with  another  thinker.  The  asso- 
ciation between  Anaxagoras  and  Democritus  cannot 
be  directly  traced,  but  it  is  an  association  which  the 
historian  of  ideas  should  never  for  a  moment  forget. 
If  we  are  not  to  be  misled  by  mere  word-jugglery,  we 
shall  recognize  the  founder  of  the  atomic  theory  of 
matter  in  Anaxagoras;  its  expositors  along  slightly 
different  lines  in  Leucippus  and  Democritus;  its  re- 
discoverer  of  the  nineteenth  century  in  Dalton.  All 
in  all,  then,  just  as  Anaxagoras  preceded  Democritus 
in  time,  so  must  he  take  precedence  over  him  also  as 
an  inductive  thinker,  who  carried  the  use  of  the  scien- 
tific imagination  to  its  farthest  reach. 

An  analysis  of  the  theories  of  the  two  men  leads  to 
somewhat  the  same  conclusion  that  might  be  reached 
from  a  comparison  of  their  lives.  Anaxagoras  was  a 
sceptical,  experimental  scientist,  gifted  also  with  the 
prophetic  imagination.  He  reasoned  always  from  the 
particular  to  the  general,  after  the  manner  of  true  in- 
duction, and  he  scarcely  took  a  step  beyond  the  con- 
fines of  secure  induction.  True  scientist  that  he  was, 
he  could  content  himself  with  postulating  different 
qualities  for  his  elements,  without  pretending  to  know 
how  these  qualities  could  be  defined.  His  elements 
were  by  hypothesis  invisible,  hence  he  would  not  at- 

169 


A    HISTORY   OF   SCIENCE 

tempt  to  visualize  them.  Democritus,  on  the  other 
hand,  refused  to  recognize  this  barrier.  Where  he 
could  not  know,  he  still  did  not  hesitate  to  guess. 
Just  as  he  conceived  his  atom  of  a  definite  form  with  a 
definite  structure,  even  so  he  conceived  that  the  at- 
mosphere about  him  was  full  of  invisible  spirits;  he 
accepted  the  current  superstitions  of  his  time.  Like 
the  average  Greeks  of  his  day,  he  even  believed  in  such 
omens  as  those  furnished  by  inspecting  the  entrails  of  a 
fowl.  These  chance  bits  of  biography  are  weather- 
vanes  of  the  mind  of  Democritus.  They  tend  to  sub- 
stantiate our  conviction  that  Democritus  must  rank 
below  Anaxagoras  as  a  devotee  of  pure  science.  But, 
after  all,  such  comparisons  and  estimates  as  this  are 
utterly  futile.  The  essential  fact  for  us  is  that  here, 
in  the  fifth  century  before  our  era,  we  find  put  forward 
the  most  penetrating  guess  as  to  the  constitution  of 
matter  that  the  history  of  ancient  thought  has  to  pre- 
sent to  us.  In  one  direction,  the  avenue  of  progress 
is  barred;  there  will  be  no  farther  step  that  way  till 
we  come  down  the  centuries  to  the  time  of  Dalton. 

HIPPOCRATES    AND    GREEK   MEDICINE 

These  studies  of  the  constitution  of  matter  have  car- 
ried us  to  the  limits  of  the  field  of  scientific  imagination 
in  antiquity;  let  us  now  turn  sharply  and  consider  a 
department  of  science  in  which  theory  joins  hands  with 
practicality.  Let  us  witness  the  beginnings  of  scien- 
tific therapeutics. 

Medicine  among  the  early  Greeks,  before  the  time 
of  Hippocrates,  was  a  crude  mixture  of  religion,  nec- 
romancy, and   mysticism.     Temples   were  erected  to 

170 


HIPPOCRATES 


GREEK  SCIENCE  IN  EARLY  ATTIC  PERIOD 

the  god  of  medicine,  ^sculapius,  and  sick  persons 
made  their  way,  or  were  carried,  to  these  temples,  where 
they  sought  to  gain  the  favor  of  the  god  by  suitable 
offerings,  and  learn  the  way  to  regain  their  health 
through  remedies  or  methods  revealed  to  them  in 
dreams  by  the  god.  When  the  patient  had  been  thus 
cured,  he  placed  a  tablet  in  the  temple  describing  his 
sickness,  and  telling  by  what  method  the  god  had  cured 
him.  He  again  made  suitable  offerings  at  the  temple, 
which  were  sometimes  in  the  form  of  gold  or  silver 
representations  of  the  diseased  organ — a  gold  or  silver 
model  of  a  heart,  hand,  foot,  etc. 

Nevertheless,  despite  this  belief  in  the  supernatural, 
many  drugs  and  healing  lotions  were  employed,  and 
the  Greek  physicians  possessed  considerable  skill  in 
dressing  wounds  and  bandaging.  But  they  did  not 
depend  upon  these  surgical  dressings  alone,  using  with 
them  certain  appropriate  prayers  and  incantations, 
recited  over  the  injured  member  at  the  time  of  apply- 
ing the  dressings. 

Even  the  very  early  Greeks  had  learned  something  of 
anatomy.  The  daily  contact  with  wounds  and  broken 
bones  must  of  necessity  lead  to  a  crude  understanding 
of  anatomy  in  general.  The  first  Greek  anatomist, 
however,  who  is  recognized  as  such,  is  said  to  have  been 
Alcmaeon.  He  is  said  to  have  made  extensive  dis- 
sections of  the  lower  animals,  and  to  have  described 
many  hitherto  unknown  structures,  such  as  the  optic 
nerve  and  the  Eustachian  canal — the  small  tube  lead- 
ing into  the  throat  from  the  ear.  He  is  credited  with 
many  unique  explanations  of  natural  phenomena,  such 
as,  for  example,  the  explanation  that  "hearing  is  pro- 

171 


A   HISTORY   OF   SCIENCE 

duced  by  the  hollow  bone  behind  the  ear ;  for  all  hollow 
things  are  sonorous."  He  was  a  rationalist,  and  he 
taught  that  the  brain  is  the  organ  of  mind.  The 
sources  of  our  information  about  his  work,  however, 
are  unreliable. 

Democedes,  who  lived  in  the  sixth  century  B.C.,  is 
the  first  physician  of  whom  we  have  any  trustworthy 
history.  We  learn  from  Herodotus  that  he  came  from 
Croton  to  ^Sgina,  where,  in  recognition  of  his  skill,  he 
was  appointed  medical  officer  of  the  city.  From 
JEgina  he  was  called  to  Athens  at  an  increased  salary, 
and  later  was  in  charge  of  medical  affairs  in  several 
other  Greek  cities.  He  was  finally  called  to  Samos  by 
the  tyrant  Polycrates,  who  reigned  there  from  about 
536  to  522  b.c.  But  on  the  death  of  Polycrates,  who 
was  murdered  by  the  Persians,  Democedes  became  a 
slave.  His  fame  as  a  physician,  however,  had  reached 
the  ears  of  the  Persian  monarch,  and  shortly  after  his 
capture  he  was  permitted  to  show  his  skill  upon  King 
Darius  himself.  The  Persian  monarch  was  suffering 
from  a  sprained  ankle,  which  his  Egyptian  surgeons 
had  been  unable  to  cure.  Democedes  not  only  cured 
the  injured  member  but  used  his  influence  in  saving 
the  lives  of  his  Egyptian  rivals,  who  had  been  con- 
demned to  death  by  the  king. 

At  another  time  he  showed  his  skill  by  curing  the 
queen,  who  was  suffering  from  a  chronic  abscess  of  long 
standing.  This  so  pleased  the  monarch  that  he  offered 
him  as  a  reward  anything  he  might  desire,  except  his 
liberty.  But  the  costly  gifts  of  Darius  did  not  satisfy 
him  so  long  as  he  remained  a  slave ;  and  determined  to 
secure  his  freedom  at  any  cost,  he  volunteered  to  lead 

172 


GREEK  SCIENCE  IN  EARLY  ATTIC  PERIOD 

some  Persian  spies  into  his  native  country,  promising 
to  use  his  influence  in  converting  some  of  the  leading 
men  of  his  nation  to  the  Persian  cause.  Laden  with 
the  wealth  that  had  been  heaped  upon  him  by  Darius, 
he  set  forth  upon  his  mission,  but  upon  reaching  his 
native  city  of  Croton  he  threw  off  his  mask,  renounced 
his  Persian  mission,  and  became  once  more  a  free 
Greek. 

While  the  story  of  Democedes  throws  little  light 
upon  the  medical  practices  of  the  time,  it  shows  that 
paid  city  medical  officers  existed  in  Greece  as  early  as 
the  fifth  and  sixth  centuries  b.c.  Even  then  there 
were  different  "schools"  of  medicine,  whose  disciples 
disagreed  radically  in  their  methods  of  treating  dis- 
eases; and  there  were  also  specialists  in  certain  dis- 
eases, quacks,  and  charlatans.  Some  physicians  de- 
pended entirely  upon  external  lotions  for  healing  all 
disorders;  others  were  " hydrotherapeutists "  or  "bath- 
physicians  ' ' ;  while  there  were  a  host  of  physicians 
who  administered  a  great  variety  of  herbs  and  drugs. 
There  were  also  magicians  who  pretended  to  heal  by 
sorcery,  and  great  numbers  of  bone-setters,  oculists, 
and  dentists. 

Many  of  the  wealthy  physicians  had  hospitals,  or 
clinics,  where  patients  were  operated  upon  and  treated. 
They  were  not  hospitals  in  our  modern  understanding 
of  the  term,  but  were  more  like  dispensaries,  where 
patients  were  treated  temporarily,  but  were  not  allowed 
to  remain  for  any  length,  of  time.  Certain  commu- 
nities established  and  supported  these  dispensaries  for 
the  care  of  the  poor. 

But   anything    approaching   a    rational   system   of 

173 


A   HISTORY   OF  SCIENCE 

medicine  was  not  established,  until  Hippocrates  of 
Cos,  the  "father  of  medicine,"  came  upon  the  scene. 
In  an  age  that  produced  Phidias,  Lysias,  Herodotus, 
Sophocles,  and  Pericles,  it  seems  but  natural  that  the 
medical  art  should  find  an  exponent  who  would  rise 
above  superstitious  dogmas  and  lay  the  foundation 
for  a  medical  science.  His  rejection  of  the  supernat- 
ural alone  stamps  the  greatness  of  his  genius.  But, 
besides  this,  he  introduced  more  detailed  observation 
of  diseases,  and  demonstrated  the  importance  that  at- 
taches to  prognosis. 

Hippocrates  was  born  at  Cos,  about  460  B.C.,  but 
spent  most  of  his  life  at  Larissa,  in  Thessaly.  He  was 
educated  as  a  physician  by  his  father,  and  travelled 
extensively  as  an  itinerant  practitioner  for  several 
years.  His  travels  in  different  climates  and  among 
many  different  people  undoubtedly  tended  to  sharpen 
his  keen  sense  of  observation.  He  was  a  practical 
physician  as  well  as  a  theorist,  and,  withal,  a  clear  and 
concise  writer.  "  Life  is  short,"  he  says,  "  opportunity 
fleeting,  judgment  difficult,  treatment  easy,  but  treat- 
ment after  thought  is  proper  and  profitable." 

His  knowledge  of  anatomy  was  necessarily  very  im- 
perfect, and  was  gained  largely  from  his  predecessors, 
to  whom  he  gave  full  credit.  Dissections  of  the  hu- 
man body  were  forbidden  him,  and  he  was  obliged  to 
confine  his  experimental  researches  to  operations 
on  the  lower  animals.  His  knowledge  of  the  struct- 
ure and  arrangement  of  the  bones,  however,  was 
fairly  accurate,  but  the  anatomy  of  the  softer  tis- 
sues, as  he  conceived  it,  was  a  queer  jumbling  to- 
gether of  blood-vessels,   muscles,   and   tendons.     He 

174 


GREEK  SCIENCE  IN  EARLY  ATTIC  PERIOD 

does  refer  to  "nerves,"  to  be  sure,  but  apparently  the 
structures  referred  to  are  the  tendons  and  ligaments, 
rather  than  the  nerves  themselves.  He  was  better 
acquainted  with  the  principal  organs  in  the  cavities  of 
the  body,  and  knew,  for  example,  that  the  heart  is 
divided  into  four  cavities,  two  of  which  he  supposed 
to  contain  blood,  and  the  other  two  air. 

His  most  revolutionary  step  was  his  divorcing  of 
the  supernatural  from  the  natural,  and  establishing 
the  fact  that  disease  is  due  to  natural  causes  and 
should  be  treated  accordingly.  The  effect  of  such  an 
attitude  can  hardly  be  over-estimated.  The  estab- 
lishment of  such  a  theory  was  naturally  followed  by  a 
close  observation  as  to  the  course  of  diseases  and  the 
effects  of  treatment.  To  facilitate  this,  he  introduced 
the  custom  of  writing  down  his  observations  as  he 
made  them — the  "clinical  history"  of  the  case.  Such 
clinical  records  are  in  use  all  over  the  world  to-day, 
and  their  importance  is  so  obvious  that  it  is  almost 
incomprehensible  that  they  should  have  fallen  into 
disuse  shortly  after  the  time  of  Hippocrates,  and  not 
brought  into  general  use  again  until  almost  two  thou- 
sand years  later. 

But  scarcely  less  important  than  his  recognition  of 
disease  as  a  natural  phenomenon  was  the  importance 
he  attributed  to  prognosis.  Prognosis,  in  the  sense  of 
prophecy,  was  common  before  the  time  of  Hippocrates. 
But  prognosis,  as  he  practised  it  and  as  we  under- 
stand it  to-day,  is  prophecy  based  on  careful  obser- 
vation of  the  course  of  diseases — something  more  than 
superstitious  conjecture. 

Although  Hippocratic  medicine  rested  on  the  belief 

i7S 


A    HISTORY   OF   SCIENCE 

in  natural  causes,  nevertheless,  dogma  and  theory  held 
an  important  place.  The  humoral  theory  of  disease 
was  an  all-important  one,  and  so  fully  was  this  theory 
accepted  that  it  influenced  the  science  of  medicine  all 
through  succeeding  centuries.  According  to"  this  cele- 
brated theory  there  are  four  humors  in  the  body — 
blood,  phlegm,  yellow  bile,  and  black  bile.  When 
these  humors  are  mixed  in  exact  proportions  they 
constitute  health ;  but  any  deviations  from  these  pro- 
portions produce  disease.  In  treating  diseases  the 
aim  of  the  physician  was  to  discover  which  of  these 
humors  were  out  of  proportion  and  to  restore  them  to 
their  natural  equilibrium.  It  was  in  the  methods  em- 
ployed in  this  restitution,  rather  than  a  disagreement 
about  the  humors  themselves,  that  resulted  in  the  va- 
rious "schools"  of  medicine. 

In  many  ways  the  surgery  of  Hippocrates  showed  a 
better  understanding  of  the  structure  of  the  organs 
than  of  their  functions.  Some  of  the  surgical  proced- 
ures as  described  by  him  are  followed,  with  slight  mod- 
ifications, to-day.  Many  of  his  methods  were  entirely 
lost  sight  of  until  modern  times,  and  one,  the  treat- 
ment of  dislocation  of  the  outer  end  of  the  collar-bone, 
was  not  revived  until  some  time  in  the  eighteenth 
century. 

Hippocrates,  it  seems,  like  modern  physicians,  some- 
times suffered  from  the  ingratitude  of  his  patients. 
"The  physician  visits  a  patient  suffering  from  fever  or 
a  wound,  and  prescribes  for  him,"  he  says ;  "  on  the  next 
day,  if  the  patient  feels  worse  the  blame  is  laid  upon 
the  physician;  if,  on  the  other  hand,  he  feels  better, 
nature  is  extolled,  and  the  physician  reaps  no  praise." 

176 


GREEK  SCIENCE  IN  EARLY  ATTIC  PERIOD 

The  essence  of  this  has  been  repeated  in  rhyme  and 
prose  by  writers  in  every  age  and  country,  but  the 
"  father  of  medicine  "  cautions  physicians  against  allow- 
ing it  to  influence  their  attitude  towards  their  pro- 
fession. 

VOL.  I. — i  a 


VIII 

POST-SOCRATIC   SCIENCE  AT   ATHENS  — PLATO. 
ARISTOTLE,   AND    THEOPHRASTUS 

DOUBTLESS  it  has  been  noticed  that  our  earlier 
scientists  were  as  far  removed  as  possible  from 
the  limitations  of  specialism.  In  point  of  fact,  in  this 
early  day,  knowledge  had  not  been  classified  as  it  came 
to  be  later  on.  The  philosopher  was,  as  his  name 
implied,  a  lover  of  knowledge,  and  he  did  not  find  it 
beyond  the  reach  of  his  capacity  to  apply  himself  to  all 
departments  of  the  field  of  human  investigation.  It 
is  nothing  strange  to  discover  that  Anaximander  and 
the  Pythagoreans  and  Anaxagoras  have  propounded 
theories  regarding  the  structure  of  the  cosmos,  the 
origin  and  development  of  animals  and  man,  and  the 
nature  of  matter  itself.  Nowadays,  so  enormously  in- 
volved has  become  the  mass  of  mere  facts  regarding 
each  of  these  departments  of  knowledge  that  no  one 
man  has  the  temerity  to  attempt  to  master  them  all. 
But  it  was  different  in  those  days  of  beginnings.  Then 
the  methods  of  observation  were  still  crude,  and  it  was 
quite  the  custom  for  a  thinker  of  forceful  personality 
to  find  an  eager  following  among  disciples  who  never 
thought  of  putting  his  theories  to  the  test  of  experi- 
ment. The  great  lesson  that  true  science  in  the  last 
resort  depends  upon  observation  and  measurement, 
upon  compass  and  balance,  had  not  yet  been  learned, 

178 


POST-SOCRATIC   SCIENCE   AT   ATHENS 

though  here  and  there  a  thinker  like  Anaxagoras  had 
gained  an  inkling  of  it. 

For  the  moment,  indeed,  there  in  Attica,  which  was 
now,  thanks  to  that  outburst  of  Periclean  culture,  the 
centre  of  the  world's  civilization,  the  trend  of  thought 
was  to  take  quite  another  direction.  The  very  year 
which  saw  the  birth  of  Democritus  at  Abdera,  and  of 
Hippocrates,  marked  also  the  birth,  at  Athens,  of  an- 
other remarkable  man,  whose  influence  it  would  scarce- 
ly be  possible  to  over-estimate.  This  man  was  Socra- 
tes. The  main  facts  of  his  history  are  familiar  to  every 
one.  It  will  be  recalled  that  Socrates  spent  his  entire 
life  in  Athens,  mingling  everywhere  with  the  popu- 
lace ;  haranguing,  so  the  tradition  goes,  every  one  who 
would  listen;  inculcating  moral  lessons,  and  finally 
incurring  the  disapprobation  of  at  least  a  voting  ma- 
jority of  his  fellow-citizens.  He  gathered  about  him 
a  company  of  remarkable  men  with  Plato  at  their 
head,  but  this  could  not  save  him  from  the  disappro- 
bation of  the  multitudes,  at  whose  hands  he  suffered 
death,  legally  administered  after  a  public  trial.  The 
facts  at  command  as  to  certain  customs  of  the  Greeks 
at  this  period  make  it  possible  to  raise  a  question  as  to 
whether  the  alleged  "  corruption  of  youth,"  with  which 
Socrates  was  charged,  may  not  have  had  a  different 
implication  from  what  posterity  has  preferred  to 
ascribe  to  it.  But  this  thought,  almost  shocking  to 
the  modern  mind  and  seeming  altogether  sacrilegious 
to  most  students  of  Greek  philosophy,  need  not  here 
detain  us;  neither  have  we  much  concern  in  the 
present  connection  with  any  part  of  the  teaching 
of   the   martyred  philosopher.     For  the  historian   of 

179 


A  HISTORY  OF  SCIENCE 

metaphysics,  Socrates  marks  an  epoch,  but  for  the 
historian  of  science  he  is  a  much  less  consequential 
figure. 

Similarly  regarding  Plato,  the  aristocratic  Athenian 
who  sat  at  the  feet  of  Socrates,  and  through  whose 
writings  the  teachings  of  the  master  found  widest  cur- 
rency. Some  students  of  philosophy  find  in  Plato 
"the  greatest  thinker  and  writer  of  all  time."  *  The 
student  of  science  must  recognize  in  him  a  thinker 
whose  point  of  view  was  essentially  non-scientific ;  one 
who  tended  always  to  reason  from  the  general  to  the 
particular  rather  than  from  the  particular  to  the  gen- 
eral. Plato's  writings  covered  almost  the  entire  field 
of  thought,  and  his  ideas  were  presented  with  such 
literary  charm  that  successive  generations  of  readers 
turned  to  them  with  unflagging  interest,  and  gave 
them  wide  currency  through  copies  that  finally  pre- 
served them  to  our  own  time.  Thus  we  are  not 
obliged  in  his  case,  as  we  are  in  the  case  of  every 
other  Greek  philosopher,  to  estimate  his  teachings 
largely  from  hearsay  evidence.  Plato  himself  speaks 
to  us  directly.  It  is  true,  the  literary  form  which  he 
always  adopted,  namely,  the  dialogue,  does  not  give 
quite  the  same  certainty  as  to  when  he  is  expressing 
his  own  opinions  that  a  more  direct  narrative  would 
have  given ;  yet,  in  the  main,  there  is  little  doubt  as  to 
the  tenor  of  his  own  opinions — except,  indeed,  such 
doubt  as  always  attaches  to  the  philosophical  reason- 
ing of  the  abstract  thinker. 

What  is  chiefly  significant  from  our  present  stand- 
point is  that  the  great  ethical  teacher  had  no  sig- 
nificant message  to  give   the  world   regarding    the 

1 80 


POST-SOCRATIC  SCIENCE  AT  ATHENS 

physical  sciences.  He  apparently  had  no  sharply  de- 
fined opinions  as  to  the  mechanism  of  the  universe ;  no 
clear  conception  as  to  the  origin  or  development  of 
organic  beings;  no  tangible  ideas  as  to  the  problems 
of  physics;  no  favorite  dreams  as  to  the  nature  of 
matter.  Virtually  his  back  was  turned  on  this  entire 
field  of  thought.  He  was  under  the  sway  of  those  innate 
ideas  which,  as  we  have  urged,  were  among  the  earliest 
inductions  of  science.  But  he  never  for  a  moment 
suspected  such  an  origin  for  these  ideas.  He  supposed 
his  conceptions  of  being,  his  standards  of  ethics,  to  lie 
back  of  all  experience;  for  him  they  were  the  most 
fundamental  and  most  dependable  of  facts.  ;  He  criti- 
cised Anaxagoras  for  having  tended  to  deduce  general 
laws  from  observation.  As  we  moderns  see  it,  such 
criticism  is  the  highest  possible  praise.  It  is  a  criticism 
that  marks  the  distinction  between  the  scientist  who 
is  also  a  philosopher  and  the  philosopher  who  has  but 
a  vague  notion  of  physical  science.  Plato  seemed, 
indeed,  to  realize  the  value  of  scientific  investigation; 
he  referred  to  the  astronomical  studies  of  the  Egyp- 
tians and  Chaldeans,  and  spoke  hopefully  of  the  results 
that  might  accrue  were  such  studies  to  be  taken  up 
by  that  Greek  mind  which,  as  he  justly  conceived,  had 
the  power  to  vitalize  and  enrich  all  that  it  touched. 
But  he  told  here  of  what  he  would  have  others  do, 
not  of  what  he  himself  thought  of  doing.  His  voice 
was  prophetic,  but  it  stimulated  no  worker  of  his  own 
time. 

Plato  himself  had  travelled  widely.  It  is  a  familiar 
legend  that  he  lived  for  years  in  Egypt,  endeavoring 
there  to  penetrate  the  mysteries  of  Egyptian  science. 

181 


A   HISTORY    OF   SCIENCE 

It  is  said  even  that  the  rudiments  of  geometry  which 
he  acquired  there  influenced  all  his  later  teachings. 
But  be  that  as  it  may,  the  historian  of  science  must 
recognize  in  the  founder  of  the  Academy  a  moral 
teacher  and  metaphysical  dreamer  and  sociologist, 
but  not,  in  the  modern  acceptance  of  the  term,  a  scien- 
tist. Those  wider  phases  of  biological  science  which 
find  their  expression  in  metaphysics,  in  ethics,  in  po- 
litical economy,  lie  without  our  present  scope ;  and  for 
the  development  of  those  subjects  with  which  we  are 
more  directly  concerned,  Plato,  like  his  master,  has  a 
negative  significance. 

ARISTOTLE  (384-322   B.C.) 

When  we  pass  to  that  third  great  Athenian  teacher, 
Aristotle,  the  case  is  far  different.  Here  was  a  man 
whose  name  was  to  be  received  as  almost  a  synonym 
for  Greek  science  for  more  than  a  thousand  years 
after  his  death.  All  through  the  Middle  Ages  his  writ- 
ings were  to  be  accepted  as  virtually  the  last  word  re- 
garding the  problems  of  nature.  We  shall  see  that  his 
followers  actually  preferred  his  mandate  to  the  testi- 
mony of  their  own  senses.  We  shall  see,  further,  that 
modern  science  progressed  somewhat  in  proportion 
as  it  overthrew  the  Aristotelian  dogmas.  But  the 
traditions  of  seventeen  or  eighteen  centuries  are  not 
easily  set  aside,  and  it  is  perhaps  not  too  much  to  say 
that  the  name  of  Aristotle  stands,  even  in  our  own 
time,  as  vaguely  representative  in  the  popular  mind 
of  all  that  was  highest  and  best  in  the  science  of  an- 
tiquity. Yet,  perhaps,  it  would  not  be  going  too  far 
to  assert  that  something  like  a  reversal  of  this  judg- 

182 


ARISTOTLE 


POST-SOCRATIC   SCIENCE   AT   ATHENS 

ment  would  be  nearer  the  truth.  Aristotle  did,  in- 
deed, bring  together  a  great  mass  of  facts  regarding 
animals  in  his  work  on  natural  history,  which,  being 
preserved,  has  been  deemed  to  entitle  its  author  to  be 
called  the  "  father  of  zoology."  But  there  is  no  reason 
to  suppose  that  any  considerable  portion  of  this  work 
contained  matter  that  was  novel,  or  recorded  observa- 
tions that  were  original  with  Aristotle ;  and  the  classi- 
fications there  outlined  are  at  best  but  a  vague  fore- 
shadowing of  the  elaboration  of  the  science.  Such  as 
it  is,  however,  the  natural  history  stands  to  the  credit 
of  the  Stagirite.  He  must  be  credited,  too,  with  a 
clear  enunciation  of  one  most  important  scientific 
doctrine — namely,  the  doctrine  of  the  spherical  figure 
of  the  earth.  We  have  already  seen  that  this  theory 
originated  with  the  Pythagorean  philosophers  out  in 
Italy.  We  have  seen,  too,  that  the  doctrine  had  not 
made  its  way  in  Attica  in  the  time  of  Anaxagoras. 
But  in  the  intervening  century  it  had  gained  wide  cur- 
rency, else  so  essentially  conservative  a  thinker  as 
Aristotle  would  scarcely  have  accepted  it.  He  did 
accept  it,  however,  and  gave  the  doctrine  clearest  and 
most  precise  expression.     Here  are  his  words:2 

"  As  to  the  figure  of  the  earth  it  must  necessarily  be 
spherical.  ...  If  it  were  not  so,  the  eclipses  of  the  moon 
would  not  have  such  sections  as  they  have.  For  in  the 
configurations  in  the  course  of  a  month  the  deficient 
part  takes  all  different  shapes;  it  is  straight,  and  con- 
cave, and  convex;  but  in  eclipses  it  always  has  the  line 
of  divisions  convex;  wherefore,  since  the  moon  is 
eclipsed  in  consequence  of  the  interposition  of  the  earth, 

183 


A   HISTORY   OF   SCIENCE 

the  periphery  of  the  earth  must  be  the  cause  of  this  by- 
having  a  spherical  form.  And  again,  from  the  appear- 
ance of  the  stars  it  is  clear,  not  only  that  the  earth  is 
round,  but  that  its  size  is  not  very  large;  for  when  we 
make  a  small  removal  to  the  south  or  the  north,  the 
circle  of  the  horizon  becomes  palpably  different,  so 
that  the  stars  overhead  undergo  a  great  change,  and 
are  not  the  same  to  those  that  travel  in  the  north  and 
to  the  south.  For  some  stars  are  seen  in  Egypt  or  at 
Cyprus,  but  are  not  seen  in  the  countries  to  the  north 
of  these;  and  the  stars  that  in  the  north  are  visible 
while  they  make  a  complete  circuit,  there  undergo  a 
setting.  So  that  from  this  it  is  manifest,  not  only  that 
the  form  of  the  earth  is  round,  but  also  that  it  is  a  part 
of  a  not  very  large  sphere ;  for  otherwise  the  difference 
would  not  be  so  obvious  to  persons  making  so  small  a 
change  of  place.  Wherefore  we  may  judge  that  those 
persons  who  connect  the  region  in  the  neighborhood 
of  the  pillars  of  Hercules  with  that  towards  India,  and 
who  assert  that  in  this  way  the  sea  is  one,  do  not  as- 
sert things  very  improbable.  They  confirm  this  con- 
jecture moreover  by  the  elephants,  which  are  said  to 
be  of  the  same  species  towards  each  extreme ;  as  if  this 
circumstance  was  a  consequence  of  the  conjunction  of 
the  extremes.  The  mathematicians  who  try  to  calcu- 
late the  measure  of  the  circumference,  make  it  amount 
to  four  hundred  thousand  stadia;  whence  we  collect 
that  the  earth  is  not  only  spherical,  but  is  not  large 
compared  with  the  magnitude  of  the  other  stars." 

But  in  giving  full  meed  of  praise  to  Aristotle  for  the 
promulgation  of  this  doctrine  of  the  sphericity  of  the 

184 


POST-SOCRATIC  SCIENCE   AT  ATHENS 

earth,  it  must  -unfortunately  be  added  that  the  con- 
servative philosopher  paused  without  taking  one  other 
important  step.  He  could  not  accept,  but,  on  the 
contrary,  he  expressly  repudiated,  the  doctrine  of  the 
earth's  motion.  We  have  seen  that  this  idea  also  was 
a  part  of  the  Pythagorean  doctrine,  and  we  shall  have 
occasion  to  dwell  more  at  length  on  this  point  in  a  suc- 
ceeding chapter.  It  has  even  been  contended  by  some 
critics  that  it  was  the  adverse  conviction  of  the  Peri- 
patetic philosopher  which,  more  than  any  other  single 
influence,  tended  to  retard  the  progress  of  the  true 
doctrine  regarding  the  mechanism  of  the  heavens. 
Aristotle  accepted  the  sphericity  of  the  earth,  and  that 
doctrine  became  a  commonplace  of  scientific  knowl- 
edge, and  so  continued  throughout  classical  antiquity. 
But  Aristotle  rejected  the  doctrine  of  the  earth's  mo- 
tion, and  that  doctrine,  though  promulgated  actively 
by  a  few  contemporaries  and  immediate  successors  of 
the  Stagirite,  was  then  doomed  to  sink  out  of  view 
for  more  than  a  thousand  years.  If  it  be  a  correct 
assumption  that  the  influence  of  Aristotle  was,  in  a 
large  measure,  responsible  for  this  result,  then  we  shall 
perhaps  not  be  far  astray  in  assuming  that  the  great 
founder  of  the  Peripatetic  school  was,  on  the  whole, 
more  instrumental  in  retarding  the  progress  of  astro- 
nomical science  that  any  other  one  man  that  ever 
lived. 

The  field  of  science  in  which  Aristotle  was  pre-emi- 
nently a  pathfinder  is  zoology.  His  writings  on  nat- 
ural history  have  largely  been  preserved,  and  they 
constitute  by  far  the  most  important  contribution 
to  the  subject  that  has  come  down  to  us  from  an- 

i85 


A   HISTORY   OF   SCIENCE 

tiquity.  They  show  us  that  Aristotle  had  gained 
possession  of  the  widest  range  of  facts  regarding  the 
animal  kingdom,  and,  what  is  far  more  important,  had 
attempted  to  classify  these  facts.  In  so  doing  he  be- 
came the  founder  of  systematic  zoology.  Aristotle's 
classification  of  the  animal  kingdom  was  known  and 
studied  throughout  the  Middle  Ages,  and,  in  fact,  re- 
mained in  vogue  until  superseded  by  that  of  Cuvier  in 
the  nineteenth  century.  It  is  not  to  be  supposed  that 
all  the  terms  of  Aristotle's  classification  originated 
with  him.  Some  of  the  divisions  are  too  patent  to 
have  escaped  the  observation  of  his  predecessors. 
Thus,  for  example,  the  distinction  between  birds  and 
fishes  as  separate  classes  of  animals  is  so  obvious  that 
it  must  appeal  to  a  child  or  to  a  savage.  But  the  ef- 
forts of  Aristotle  extended,  as  we  shall  see,  to  less 
patent  generalizations.  At  the  very  outset,  his  grand 
division  of  the  animal  kingdom  into  blood-bearing  and 
bloodless  animals  implies  a  very  broad  and  philo- 
sophical conception  of  the  entire  animal  kingdom. 
The  modern  physiologist  does  not  accept  the  classifica- 
tion, inasmuch  as  it  is  now  known  that  colorless  fluids 
perform  the  functions  of  blood  for  all  the  lower  organ- 
isms. But  the  fact  remains  that  Aristotle's  grand 
divisions  correspond  to  the  grand  divisions  of  the 
Lamarckian  system — vertebrates  and  invertebrates — 
which  every  one  now  accepts.  Aristotle,  as  we  have 
said,  based  his  classification  upon  observation  of  the 
blood ;  Lamarck  was  guided  by  a  study  of  the  skeleton. 
The  fact  that  such  diverse  points  of  view  could  direct 
the  observer  towards  the  same  result  gives,  infer- 
entially,    a    suggestive  lesson   in   what    the    modern 

1 86 


POST-SOCRATIC   SCIENCE   AT  ATHENS 

physiologist  calls  the  homologies  of  parts  of  the 
organism. 

Aristotle  divides  his  so-called  blood-bearing  animals 
into  five  classes:  (i)  Four-footed  animals  that  bring 
forth  their  young  alive;  (2)  birds;  (3)  egg-laying  four- 
footed  animals  (including  what  modern  naturalists 
call  reptiles  and  amphibians) ;  (4)  whales  and  their 
allies;  (5)  fishes.  This  classification,  as  will  be  ob- 
served, is  not  so  very  far  afield  from  the  modern  di- 
visions into  mammals,  birds,  reptiles,  amphibians,  and 
fishes.  That  Aristotle  should  have  recognized  the 
fundamental  distinction  between  fishes  and  the  fish- 
like whales,  dolphins,  and  porpoises  proves  the  far 
from  superficial  character  of  his  studies.  Aristotle 
knew  that  these  animals  breathe  by  means  of  lungs  and 
that  they  produce  living  young.  He  recognized,  there- 
fore, their  affinity  with  his  first  class  of  animals,  even 
if  he  did  not,  like  the  modern  naturalist,  consider  these 
affinities  close  enough  to  justify  bringing  the  two  types 
together  into  a  single  class. 

The  bloodless  animals  were  also  divided  by  Aris- 
totle into  five  classes — namely:  (1)  Cephalopoda  (the 
octopus,  cuttle-fish,  etc.) ;  (2)  weak-shelled  animals 
(crabs,  etc.) ;  (3)  insects  and  their  allies  (including 
various  forms,  such  as  spiders  and  centipedes,  which 
the  modern  classifier  prefers  to  place  by  themselves) ; 

(4)  hard-shelled  animals  (clams,  oysters,  snails,  etc.); 

(5)  a  conglomerate  group  of  marine  forms,  including 
star-fish,  sea-urchins,  and  various  anomalous  forms 
that  were  regarded  as  linking  the  animal  to  the  vege- 
table worlds.  This  classification  of  the  lower  forms  of 
animal  life  continued  in  vogue  until  Cuvier  substituted 

187 


A   HISTORY    OF   SCIENCE 

for  it  his  famous  grouping  into  articulates,  mollusks, 
and  radiates ;  which  grouping  in  turn  was  in  part  super- 
seded later  in  the  nineteenth  century. 

What  Aristotle  did  for  the  animal  kingdom  his  pupil, 
Theophrastus,  did  in  some  measure  for  the  vegetable 
kingdom.  Theophrastus,  however,  was  much  less  a 
classifier  than  his  master,  and  his  work  on  botany, 
called  The  Natural  History  of  Development,  pays  com- 
paratively slight  attention  to  theoretical  questions. 
It  deals  largely  with  such  practicalities  as  the  making 
of  charcoal,  of  pitch,  and  of  resin,  and  the  effects  of 
various  plants  on  the  animal  organism  when  taken  as 
foods  or  as  medicines.  In  this  regard  the  work  of 
Theophrastus  is  more  nearly  akin  to  the  natural  his- 
tory of  the  famous  Roman  compiler,  Pliny.  It  re- 
mained, however,  throughout  antiquity  as  the  most 
important  work  on  its  subject,  and  it  entitles  Theo- 
phrastus to  be  called  the  "  father  of  botany."  Theo- 
phrastus deals  also  with  the  mineral  kingdom  after 
much  the  same  fashion,  and  here  again  his  work  is  the 
most  notable  that  was  produced  in  antiquity. 


IX 

GREEK  SCIENCE  OF  THE  ALEXANDRIAN  OR 
HELLENISTIC   PERIOD 

WE  are  entering  now  upon  the  most  important 
scientific  epoch  of  antiquity.  When  Aristotle 
and  Theophrastus  passed  from  the  scene,  Athens 
ceased  to  be  in  any  sense  the  scientific  centre  of  the 
world.  That  city  still  retained  its  reminiscent  glory, 
and  cannot  be  ignored  in  the  history  of  culture,  but 
no  great  scientific  leader  was  ever  again  to  be  born  or 
to  take  up  his  permanent  abode  within  the  confines 
of  Greece  proper.  With  almost  cataclysmic  sudden- 
ness, a  new  intellectual  centre  appeared  on  the  south 
shore  of  the  Mediterranean.  This  was  the  city  of 
Alexandria,  a  city  which  Alexander  the  Great  had 
founded  during  his  brief  visit  to  Egypt,  and  which 
became  the  capital  of  Ptolemy  Soter  when  he  chose 
Egypt  as  his  portion  of  the  dismembered  empire  of 
the  great  Macedonian.  Ptolemy  had  been  with  his 
master  in  the  East,  and  was  with  him  in  Babylonia 
when  he  died.  He  had  therefore  come  personally 
in  contact  with  Babylonian  civilization,  and  we 
cannot  doubt  that  this  had  a  most  important  influ- 
ence upon  his  life,  and  through  him  upon  the  new 
civilization  of  the  West.  In  point  of  culture,  Alexan- 
dria must  be  regarded  as  the  successor  of  Babylon, 
scarcely  less  directly  than  of  Greece.     Following  the 

189 


A   HISTORY   OF   SCIENCE 

Babylonian  model,  Ptolemy  erected  a  great  museum 
and  began  collecting  a  library.  Before  his  death  it 
was  said  that  he  had  collected  no  fewer  than  two  hun- 
dred thousand  manuscripts.  He  had  gathered  also  a 
company  of  great  teachers  and  founded  a  school  of 
science  which,  as  has  just  been  said,  made  Alexandria 
the  culture-centre  of  the  world. 

Athens  in  the  day  of  her  prime  had  known  nothing 
quite  like  this.  Such  private  citizens  as  Aristotle  are 
known  to  have  had  libraries,  but  there  were  no  great 
public  collections  of  books  in  Athens,  or  in  any  other 
part  of  the  Greek  domain,  until  Ptolemy  founded  his 
famous  library.  As  is  well  known,  such  libraries  had 
existed  in  Babylonia  for  thousands  of  years.  The 
character  which  the  Ptolemaic  epoch  took  on  was  no 
doubt  due  to  Babylonian  influence,  but  quite  as  much 
to  the  personal  experience  of  Ptolemy  himself  as  an 
explorer  in  the  Far  East.  The  marvellous  conquering 
journey  of  Alexander  had  enormously  widened  the 
horizon  of  the  Greek  geographer,  and  stimulated  the 
imagination  of  all  ranks  of  the  people.  It  was  but 
natural,  then,  that  geography  and  its  parent  science 
astronomy  should  occupy  the  attention  of  the  best 
minds  in  this  succeeding  epoch.  In  point  of  fact,  such 
a  company  of  star-gazers  and  earth-measurers  came 
upon  the  scene  in  this  third  century  b.c.  as  had  never 
before  existed  anywhere  in  the  world.  The  whole 
trend  of  the  time  was  towards  mechanics.  It  was  as 
if  the  greatest  thinkers  had  squarely  faced  about  from 
the  attitude  of  the  mystical  philosophers  of  the  pre- 
ceding century,  and  had  set  themselves  the  task  of 
solving  all  the  mechanical  riddles  of  the  universe. 

190 


ALEXANDRIAN  OR  HELLENISTIC  PERIOD 

They  no  longer  troubled  themselves  about  problems 
of  "being"  and  "becoming" ;  they  gave  but  little  heed 
to  metaphysical  subtleties;  they  demanded  that  their 
thoughts  should  be  gauged  by  objective  realities. 
Hence  there  arose  a  succession  of  great  geometers,  and 
their  conceptions  were  applied  to  the  construction  of 
new  mechanical  contrivances  on  the  one  hand,  and 
to  the  elaboration  of  theories  of  sidereal  mechanics 
on  the  other. 

The  wonderful  company  of  men  who  performed  the 
feats  that  are  about  to  be  recorded  did  not  all  find 
their  home  in  Alexandria,  to  be  sure ;  but  they  all  came 
more  or  less  under  the  Alexandrian  influence.  We 
shall  see  that  there  are  two  other  important  centres; 
one  out  in  Sicily,  almost  at  the  confines  of  the  Greek 
territory  in  the  west ;  the  other  in  Asia  Minor,  notably 
on  the  island  of  Samos — the  island  which,  it  will  be 
recalled,  was  at  an  earlier  day  the  birthplace  of  Pythag- 
oras. But  whereas  in  the  previous  century  colonists 
from  the  confines  of  the  civilized  world  came  to  Athens, 
now  all  eyes  turned  towards  Alexandria,  and  so  im- 
proved were  the  facilities  for  communication  that  no 
doubt  the  discoveries  of  one  coterie  of  workers  were 
known  to  all  the  others  much  more  quickly  than  had 
ever  been  possible  before.  We  learn,  for  example, 
that  the  studies  of  Aristarchus  of  Samos  were  definitely 
known  to  Archimedes  of  Syracuse,  out  in  Sicily.  In- 
deed, as  we  shall  see,  it  is  through  a  chance  reference 
preserved  in  one  of.  the  writings  of  Archimedes  that 
one  of  the  most  important  speculations  of  Aristarchus 
is  made  known  to  us.  This  illustrates  sufficiently  the 
intercommunication  through  which  the  thought  of  the 

191 


A   HISTORY   OF   SCIENCE 

Alexandrian  epoch  was  brought  into  a  single  channel. 
We  no  longer,  as  in  the  day  of  the  earlier  schools  of 
Greek  philosophy,  have  isolated  groups  of  thinkers. 
The  scientific  drama  is  now  played  out  upon  a  sin- 
gle stage;  and  if  we  pass,  as  we  shall  in  the  pres- 
ent chapter,  from  Alexandria  to  Syracuse  and  from 
Syracuse  to  Samos,  the  shift  of  scenes  does  no  violence 
to  the  dramatic  unities. 

Notwithstanding  the  number  of  great  workers  who 
were  not  properly  Alexandrians,  none  the  less  the  epoch 
is  with  propriety  termed  Alexandrian.  Not  merely  in 
the  third  century  B.C.,  but  throughout  the  lapse  of  at 
least  four  succeeding  centuries,  the  city  of  Alexander 
and  the  Ptolemies  continued  to  hold  its  place  as  the 
undisputed  culture-centre  of  the  world.  During  that 
period  Rome  rose  to  its  pinnacle  of  glory  and  began 
to  decline,  without  ever  challenging  the  intellectual 
supremacy  of  the  Egyptian  city.  We  shall  see,  in  a 
later  chapter,  that  the  Alexandrian  influences  were 
passed  on  to  the  Mohammedan  conquerors,  and  every 
one  is  aware  that  when  Alexandria  was  finally  over- 
thrown its  place  was  taken  by  another  Greek  city,  By- 
zantium or  Constantinople.  But  that  transfer  did  not 
occur  until  Alexandria  had  enjoyed  a  longer  period  of 
supremacy  as  an  intellectual  centre  than  had  perhaps 
ever  before  been  granted  to  any  city,  with  the  possi- 
sible  exception  of  Babylon. 

EUCLID  (ABOUT   3OO    B.C.) 

Our  present  concern  is  with  that  first  wonderful 
development  of  scientific  activity  which  began  under 
the  first  Ptolemy,  and  which  presents,  in  the  course  of 

192 


ALEXANDRIAN  OR  HELLENISTIC  PERIOD 

the  first  century  of  Alexandrian  influence,  the  most 
remarkable  coterie  of  scientific  workers  and  thinkers 
that  antiquity  produced.  The  earliest  group  of  these 
new  leaders  in  science  had  at  its  head  a  man  whose 
name  has  been  a  household  word  ever  since.  This  was 
Euclid,  the  father  of  systematic  geometry.  Tradition 
has  preserved  to  us  but  little  of  the  personality  of  this 
remarkable  teacher;  but,  on  the  other  hand,  his  most 
important  work  has  come  down  to  us  in  its  entirety. 
The  Elements  of  Geometry,  with  which  the  name  of 
Euclid  is  associated  in  the  mind  of  every  school-boy, 
presented  the  chief  propositions  of  its  subject  in  so  sim- 
ple and  logical  a  form  that  the  work  remained  a  text- 
book everywhere  for  more  than  two  thousand  years. 
Indeed  it  is  only  now  beginning  to  be  superseded.  It 
is  not  twenty  years  since  English  mathematicians 
could  deplore  the  fact  that,  despite  certain  rather  ob- 
vious defects  of  the  work  of  Euclid,  no  better  text- 
book than  this  was  available.  Euclid's  work,  of  course, 
gives  expression  to  much  knowledge  that  did  not  origi- 
nate with  him.  We  have  already  seen  that  several  im- 
portant propositions  of  geometry  had  been  developed 
by  Thales,  and  one  by  Pythagoras,  and  that  the  ru- 
diments of  the  subject  were  at  least  as  old  as  Egyp- 
tian civilization.  Precisely  how  much  Euclid  added 
through  his  own  investigations  cannot  be  ascertained. 
It  seems  probable  that  he  was  a  diffuser  of  knowledge 
rather  than  an  originator,  but  as  a  great  teacher  his 
fame  is  secure.  He  is  credited  with  an  epigram  which 
in  itself  might  insure  him  perpetuity  of  fame :  "  There  is 
no  royal  road  to  geometry,"  was  his  answer  to  Ptolemy 
when  that  ruler  had  questioned  whether  the  Elements 
vol.  i.— 13  193 


A   HISTORY   OF   SCIENCE 

might  not  be   simplified.     Doubtless  this,   like  most 
similar  good  sayings,  is  apocryphal;  but  whoever  in 
vented  it  has  made  the  world  his  debtor. 

HEROPHILUS    AND    ERASISTRATUS 

The  catholicity  of  Ptolemy's  tastes  led  him,  natu- 
rally enough,  to  cultivate  the  biological  no  less  than 
the  physical  sciences.  In  particular  his  influence  per- 
mitted an  epochal  advance  in  the  field  of  medicine. 
Two  anatomists  became  famous  through  the  investiga- 
tions they  were  permitted  to  make  under  the  patron- 
age of  the  enlightened  ruler.  These  earliest  of  really 
scientific  investigators  of  the  mechanism  of  the  human 
body  were  named  Herophilus  and  Erasistratus.  These 
two  anatomists  gained  their  knowledge  by  the  dissec- 
tion of  human  bodies  (theirs  are  the  first  records  that 
we  have  of  such  practices),  and  King  Ptolemy  himself 
is  said  to  have  been  present  at  some  of  these  dissec- 
tions. They  were  the  first  to  discover  that  the  nerve- 
trunks  have  their  origin  in  the  brain  and  spinal  cord, 
and  they  are  credited  also  with  the  discovery  that  these 
nerve-trunks  are  of  two  different  kinds — one  to  con- 
vey motor,  and  the  other  sensory  impulses.  They 
discovered,  described,  and  named  the  coverings  of  the 
brain.  The  name  of  Herophilus  is  still  applied  by 
anatomists,  in  honor  of  the  discoverer,  to  one  of  the 
sinuses  or  large  canals  that  convey  the  venous  blood 
from  the  head.  Herophilus  also  noticed  and  described 
four  cavities  or  ventricles  in  the  brain,  and  reached  the 
conclusion  that  one  of  these  ventricles  was  the  seat  of 
the  soul — a  belief  shared  until  comparatively  recent 
times  by  many  physiologists.     He  made  also  a  careful 

194 


ALEXANDRIAN  OR  HELLENISTIC  PERIOD 

and  fairly  accurate  study  of  the  anatomy  of  the  eye, 
and  greatly  improved  the  old  operation  for  cataract. 

With  the  increased  knowledge  of  anatomy  came  also 
corresponding  advances  in  surgery,  and  many  experi- 
mental operations  are  said  to  have  been  performed 
upon  condemned  criminals  who  were  handed  over  to 
the  surgeons  by  the  Ptolemies.  While  many  modern 
writers  have  attempted  to  discredit  these  assertions, 
it  is  not  improbable  that  such  operations  were  per- 
formed. In  an  age  when  human  life  was  held  so  cheap, 
and  among  a  people  accustomed  to  torturing  con- 
demned prisoners  for  comparatively  slight  offences,  it 
is  not  unlikely  that  the  surgeons  were  allowed  to  inflict 
perhaps  less  painful  tortures  in  the  cause  of  science. 
Furthermore,  we  know  that  condemned  criminals  were 
sometimes  handed  over  to  the  medical  profession  to 
be  "  operated  upon  and  killed  in  whatever  way  they 
thought  best "  even  as  late  as  the  sixteenth  century. 
Tertullian  l  probably  exaggerates,  however,  when  he 
puts  the  number  of  such  victims  in  Alexandria  at  six 
hundred. 

Had  Herophilus  and  Erasistratus  been  as  happy  in 
their  deductions  as  to  the  functions  of  the  organs  as 
they  were  in  their  knowledge  of  anatomy,  the  science 
of  medicine  would  have  been  placed  upon  a  very  high 
plane  even  in  their  time.  Unfortunately,  however, 
they  not  only  drew  erroneous  inferences  as  to  the  func- 
tions of  the  organs,  but  also  disagreed  radically  as  to 
what  functions  certain  organs  performed,  and  how  dis- 
eases should  be  treated,  even  when  agreeing  perfectly 
on  the  subject  of  anatomy  itself.  Their  contribution 
to  the  knowledge  of  the  scientific  treatment  of  diseases 

195 


A   HISTORY   OF   SCIENCE 

holds  no  such  place,  therefore,  as  their  anatomical  in- 
vestigations. 

Half  a  century  after  the  time  of  Herophilus  there 
appeared  a  Greek  physician,  Heraclides,  whose  repu- 
tation in  the  use  of  drugs  far  surpasses  that  of  the 
anatomists  of  the  Alexandrian  school.  His  reputation 
has  been  handed  down  through  the  centuries  as  that 
of  a  physician,  rather  than  a  surgeon,  although  in  his 
own  time  he  was  considered  one  of  the  great  surgeons 
of  the  period.  Heraclides  belonged  to  the  "  Empiric" 
school,  which  rejected  anatomy  as  useless,  depending 
entirely  on  the  use  of  drugs.  He  is  thought  to  have 
been  the  first  physician  to  point  out  the  value  of 
opium  in  certain  painful  diseases.  His  prescription 
of  this  drug  for  certain  cases  of  "  sleeplessness,  spasm, 
cholera,  and  colic,"  shows  that  his  use  of  it  was  not 
unlike  that  of  the  modern  physician  in  certain  cases; 
and  his  treatment  of  fevers,  by  keeping  the  patient's 
head  cool  and  facilitating  the  secretions  of  the  body, 
is  still  recognized  as  "good  practice."  He  advocated 
a  free  use  of  liquids  in  quenching  the  fever  patient's 
thirst — a  recognized  therapeutic  measure  to-day,  but 
one  that  was  widely  condemned  a  century  ago. 

ARCHIMEDES    OF    SYRACUSE    AND    THE    FOUNDATION    OF 
MECHANICS 

We  do  not  know  just  when  Euclid  died,  but  as  he 
was  at  the  height  of  his  fame  in  the  time  of  Ptolemy  I., 
whose  reign  ended  in  the  year  285  b.c,  it  is  hardly 
probable  that  he  was  still  living  when  a  young  man 
named  Archimedes  came  to  Alexandria  to  study. 
Archimedes  was  born  in  the  Greek  colony  of  Syracuse, 

196 


ALEXANDRIAN  OR  HELLENISTIC  PERIOD 

on  the  island  of  Sicily,  in  the  year  287  b.c.  When  he 
visited  Alexandria  he  probably  found  Apollonius  of 
Perga,  the  pupil  of  Euclid,  at  the  head  of  the  mathe- 
matical school  there.  Just  how  long  Archimedes  re- 
mained at  Alexandria  is  not  known.  When  he  had 
satisfied  his  curiosity  or  completed  his  studies,  he  re- 
turned to  Syracuse  and  spent  his  life  there,  chiefly 
under  the  patronage  of  King  Hiero,  who  seems  fully 
to  have  appreciated  his  abilities. 

Archimedes  was  primarily  a  mathematician.  Left 
to  his  own  devices,  he  would  probably  have  devoted 
his  entire  time  to  the  study  of  geometrical  problems. 
But  King  Hiero  had  discovered  that  his  protege'  had 
wonderful  mechanical  ingenuity,  and  he  made  good  use 
of  this  discovery.  Under  stress  of  the  king's  urgings, 
the  philosopher  was  led  to  invent  a  great  variety  of 
mechanical  contrivances,  some  of  them  most  curious 
ones.  Antiquity  credited  him  with  the  invention  of 
more  than  forty  machines,  and  it  is  these,  rather  than 
his  purely  mathematical  discoveries,  that  gave  his 
name  popular  vogue  both  among  his  contemporaries 
and  with  posterity.  Every  one  has  heard  of  the  screw 
of  Archimedes,  through  which  the  paradoxical  effect 
was  produced  of  making  water  seem  to  flow  up  hill. 
The  best  idea  of  this  curious  mechanism  is  obtained  if 
one  will  take  in  hand  an  ordinary  corkscrew,  and  im- 
agine this  instrument  to  be  changed  into  a  hollow  tube, 
retaining  precisely  the  same  shape  but  increased  to 
some  feet  in  length  and  to  a  proportionate  diameter. 
If  one  will  hold  the  corkscrew  in  a  slanting  direction 
and  turn  it  slowly  to  the  right,  supposing  that  the 
point  dips  up  a  portion  of  water  each  time  it  revolves, 

197 


A   HISTORY   OF  SCIENCE 

one  can  in  imagination  follow  the  flow  of  that  por- 
tion of  water  from  spiral  to  spiral,  the  water  always 
running  downward,  of  course,  yet  paradoxically  being 
lifted  higher  and  higher  towards  the  base  of  the  cork- 
screw, until  finally  it  pours  out  (in  the  actual  Archi- 
medes' tube)  at  the  top.  There  is  another  form  of  the 
screw  in  which  a  revolving  spiral  blade  operates  with- 
in a  cylinder,  but  the  principle  is  precisely  the  same. 
With  either  form  water  may  be  lifted,  by  the  mere 
turning  of  the  screw,  to  any  desired  height.  The  in- 
genious mechanism  excited  the  wonder  of  the  contem- 
poraries of  Archimedes,  as  well  it  might.  More  efficient 
devices  have  superseded  it  in  modern  times,  but  it 
still  excites  the  admiration  of  all  who  examine  it,  and 
its  effects  seem  as  paradoxical  as  ever. 

Some  other  of  the  mechanisms  of  Archimedes  have 
been  made  known  to  successive  generations  of  readers 
through  the  pages  of  Polybius  and  Plutarch.  These 
are  the  devices  through  which  Archimedes  aided  King 
Hiero  to  ward  off  the  attacks  of  the  Roman  general 
Marcellus,  who  in  the  course  of  the  second  Punic  war 
laid  siege  to  Syracuse. 

Plutarch,  in  his  life  of  Marcellus,  describes  the  Ro- 
man's attack  and  Archimedes'  defence  in  much  detail. 
Incidentally  he  tells  us  also  how  Archimedes  came  to 
make  the  devices  that  rendered  the  siege  so  famous: 

"Marcellus  himself,  with  threescore  galleys  of  five 
rowers  at  every  bank,  well  armed  and  full  of  all  sorts 
of  artillery  and  fireworks,  did  assault  by  sea,  and  rowed 
hard  to  the  wall,  having  made  a  great  engine  and  de- 
vice of  battery,  upon  eight  galleys  chained  together, 

198 


ARCHIMEDES 
(From  an  old  print.) 


ALEXANDRIAN  OR  HELLENISTIC  PERIOD 

to  batter  the  wall:  trusting  in  the  great  multitude  of 
his  engines  of  battery,  and  to  all  such  other  necessary- 
provision  as  he  had  for  wars,  as  also  in  his  own  reputa- 
tion. But  Archimedes  made  light  account  of  all  his 
devices,  as  indeed  they  were  nothing  comparable  to 
the  engines  himself  had  invented.  This  inventive  art 
to  frame  instruments  and  engines  (which  are  called 
mechanical,  or  organical,  so  highly  commended  and 
esteemed  of  all  sorts  of  people)  was  first  set  forth  by 
Architas,  and  by  Eudoxus:  partly  to  beautify  a  little 
the  science  of  geometry  by  this  fineness,  and  partly 
to  prove  and  confirm  by  material  examples  and  sensi- 
ble instruments,  certain  geometrical  conclusions,  where- 
of a  man  cannot  find  out  the  conceivable  demonstra- 
tions by  enforced  reasons  and  proofs.  As  that  con- 
clusion which  instructeth  one  to  search  out  two  lines 
mean  proportional,  which  cannot  be  proved  by  reason 
demonstrative,  and  yet  notwithstanding  is  a  principle 
and  an  accepted  ground  for  many  things  which  are  con- 
tained in  the  art  of  portraiture.  Both  of  them  have 
fashioned  it  to  the  workmanship  of  certain  instru- 
ments, called  mesolabes  or  mesographs,  which  serve 
to  find  these  mean  lines  proportional,  by  drawing  cer- 
tain curve  lines,  and  overthwart  and  oblique  sections. 
But  after  that  Plato  was  offended  with  them,  and 
maintained  against  them,  that  they  did  utterly  cor- 
rupt and  disgrace,  the  worthiness  and  excellence  of 
geometry,  making  it  to  descend  from  things  not  com- 
prehensible and  without  body,  unto  things  sensible 
and  material,  and  to  bring  it  to  a  palpable  substance, 
where  the  vile  and  base  handiwork  of  man  is  to  be  em- 
ployed :  since  that  time,  I  say,  handicraft,  or  the  art  of 

199 


A   HISTORY   OF   SCIENCE 

engines,  came  to  be  separated  from  geometry,  and  be- 
ing long  time  despised  by  the  philosophers,  it  came  to 
be  one  of  the  warlike  arts. 

"  But  Archimedes  having  told  King  Hiero,  his  kins- 
man and  friend,  that  it  was  possible  to  remove  as  great 
a  weight  as  he  would,  with  as  little  strength  as  he 
listed  to  put  to  it :  and  boasting  himself  thus  (as  they 
report  of  him)  and  trusting  to  the  force  of  his  reasons, 
wherewith  he  proved  this  conclusion,  that  if  there  were 
another  globe  of  earth,  he  was  able  to  remove  this  of 
ours,  and  pass  it  over  to  the  other:  King  Hiero  won- 
dering to  hear  him,  required  him  to  put  his  device  in 
execution,  and  to  make  him  see  by  experience,  some 
great  or  heavy  weight  removed,  by  little  force.  So 
Archimedes  caught  hold  with  a  hook  of  one  of  the 
greatest  carects,  or  hulks  of  the  king  (that  to  draw  it  to 
the  shore  out  of  the  water  required  a  marvellous  num- 
ber of  people  to  go  about  it,  and  was  hardly  to  be  done 
so)  and  put  a  great  number  of  men  more  into  her, 
than  her  ordinary  burden :  and  he  himself  sitting  alone 
at  his  ease  far  off,  without  any  straining  at  all,  draw- 
ing the  end  of  an  engine  with  many  wheels  and  pulleys, 
fair  and  softly  with  his  hand,  made  it  come  as  gently 
and  smoothly  to  him,  as  it  had  floated  in  the  sea. 
The  king  wondering  to  see  the  sight,  and  knowing  by 
proof  the  greatness  of  his  art ;  he  prayed  him  to  make 
him  some  engines,  both  to  assault  and  defend,  in  all 
manner  of  sieges  and  assaults.  So  Archimedes  made 
him  many  engines,  but  King  Hiero  never  occupied  any 
of  them,  because  he  reigned  the  most  part  of  his  time 
in  peace  without  any  wars.  But  this  provision  and 
munition  of  engines,  served  the  Syracusan's  turn  mar- 

200 


ALEXANDRIAN  OR  HELLENISTIC  PERIOD 

vellously  at  that  time:  and  not  only  the  provision  of 
the  engines  ready  made,  but  also  the  engineer  and 
work-master  himself,  that  had  invented  them. 

"Now  the  Syracusans,  seeing  themselves  assaulted 
by  the  Romans,  both  by  sea  and  by  land,  were  mar- 
vellously perplexed,  and  could  not  tell  what  to  say, 
they  were  so  afraid:  imagining  it  was  impossible  for 
them  to  withstand  so  great  an  army.  But  when  Archi- 
medes fell  to  handling  his  engines,  and  to  set  them  at 
liberty,  there  flew  in  the  air  infinite  kinds  of  shot,  and 
marvellous  great  stones,  with  an  incredible  noise  and 
force  on  the  sudden,  upon  the  footmen  that  came  to 
assault  the  city  by  land,  bearing  down,  and  tearing  in 
pieces  all  those  which  came  against  them,  or  in  what 
place  soever  they  lighted,  no  earthly  body  being  able 
to  resist  the  violence  of  so  heavy  a  weight :  so  that  all 
their  ranks  were  marvellously  disordered.  And  as  for 
the  galleys  that  gave  assault  by  sea,  some  were  sunk 
with  long  pieces  of  timber  like  unto  the  yards  of  ships, 
whereto  they  fasten  their  sails,  which  were  suddenly 
blown  over  the  walls  with  force  of  their  engines  into 
their  galleys,  and  so  sunk  them  by  their  over  great 
weight." 

Polybius  describes  what  was  perhaps  the  most  im- 
portant of  these  contrivances,  which  was,  he  tells  us, 
"  a  hand  of  iron,  hanging  by  a  chain  from  the  beak  of  a 
machine,  which  was  used  in  the  following  manner. 
The  person  who,  like  a  pilot,  guided  the  beak,  having 
let  fall  the  hand,  and  catched  hold  of  the  prow  of  any 
vessel,  drew  down  the  opposite  end  of  the  machine 
that  was  on  the  inside  of  the  walls.     And  when  the  ves- 

201 


A   HISTORY   OF   SCIENCE 

sel  was  thus  raised  erect  upon  its  stern,  the  machine 
itself  was  held  immovable ;  but,  the  chain  being  sud- 
denly loosened  from  the  beak  by  the  means  of  pulleys, 
some  of  the  vessels  were  thrown  upon  their  sides, 
others  turned  with  the  bottom  upwards ;  and  the  great- 
est part,  as  the  prows  were  plunged  from  a  considerable 
height  into  the  sea,  were  filled  with  water,  and  all  that 
were  on  board  thrown  into  tumult  and  disorder. 

"Marcellus  was  in  no  small  degree  embarrassed,'' 
Polybius  continues,  "when  he  found  himself  encoun- 
tered in  every  attempt  by  such  resistance.  He  per- 
ceived that  all  his  efforts  were  defeated  with  loss ;  and 
were  even  derided  by  the  enemy.  But,  amidst  all  the 
anxiety  that  he  suffered,  he  could  not  help  jesting  upon 
the  inventions  of  Archimedes.  This  man,  said  he, 
employs  our  ships  as  buckets  to  draw  water :  and  box- 
ing about  our  sackbuts,  as  if  they  were  unworthy  to 
be  associated  with  him,  drives  them  from  his  company 
with  disgrace.  Such  was  the  success  of  the  siege  on 
the  side  of  the  sea." 

Subsequently,  however,  Marcellus  took  the  city  by 
strategy,  and  Archimedes  was  killed,  contrary,  it  is 
said,  to  the  express  orders  of  Marcellus.  "Syracuse 
being  taken,"  says  Plutarch,  "nothing  grieved  Mar- 
cellus more  than  the  loss  of  Archimedes.  Who,  being 
in  his  study  when  the  city  was  taken,  busily  seeking 
out  by  himself  the  demonstration  of  some  geometrical 
proposition  which  he  had  drawn  in  figure,  and  so  ear- 
nestly occupied  therein,  as  he  neither  saw  nor  heard 
any  noise  of  enemies  that  ran  up  and  down  the  city, 
and  much  less  knew  it  was  taken :  he  wondered  when 
he  saw  a  soldier  by  him,  that  bade  him  go  with  him 

202 


ALEXANDRIAN  OR  HELLENISTIC   PERIOD 

to  Marcellus.  Notwithstanding,  he  spake  to  the  sol- 
dier, and  bade  him  tarry  until  he  had  done  his  con- 
clusion, and  brought  it  to  demonstration:  but  the 
soldier  being  angry  with  his  answer,  drew  out  his 
sword  and  killed  him.  Others  say,  that  the  Roman 
soldier  when  he  came,  offered  the  sword's  point  to 
him.,  to  kill  him:  and  that  Archimedes  when  he  saw 
him,  prayed  him  to  hold  his  hand  a  little,  that  he 
might  not  leave  the  matter  he  looked  for  imperfect, 
without  demonstration.  But  the  soldier  making  no 
reckoning  of  his  speculation,  killed  him  presently.  It 
is  reported  a  third  way  also,  saying  that  certain  sol- 
diers met  him  in  the  streets  going  to  Marcellus,  car- 
rying certain  mathematical  instruments  in  a  little 
pretty  coffer,  as  dials  for  the  sun,  spheres,  and  angles, 
wherewith  they  measure  the  greatness  of  the  body  of 
the  sun  by  view:  and  they  supposing  he  had  carried 
some  gold  or  silver,  or  other  precious  jewels  in  that  little 
coffer,  slew  him  for  it.  But  it  is  most  certain  that 
Marcellus  was  marvellously  sorry  for  his  death,  and 
ever  after  hated  the  villain  that  slew  him,  as  a  cursed 
and  execrable  person :  and  how  he  had  made  also  mar- 
vellous much  afterwards  of  Archimedes'  kinsmen  for 
his  sake." 

We  are  further  indebted  to  Plutarch  for  a  summary 
of  the  character  and  influence  of  Archimedes,  and  for 
an  interesting  suggestion  as  to  the  estimate  which  the 
great  philosopher  put  upon  the  relative  importance  of 
his  own  discoveries.  "Notwithstanding  Archimedes 
had  such  a  great  mind,  and  was  so  profoundly  learned, 
having  hidden  in  him  the  only  treasure  and  secrets  of 
geometrical  inventions:  as  he  would  never  set  forth 

203 


A   HISTORY   OF   SCIENCE 

any  book  how  to  make  all  these  warlike  engines, 
which  won  him  at  that  time  the  fame  and  glory,  not 
of  man's  knowledge,  but  rather  of  divine  wisdom. 
But  he  esteeming  all  kind  of  handicraft  and  invention 
to  make  engines,  and  generally  all  manner  of  sciences 
bringing  common  commodity  by  the  use  of  them,  to  be 
but  vile,  beggarly,  and  mercenary  dross :  employed  his 
wit  and  study  only  to  write  things,  the  beauty  and 
subtlety  whereof  were  not  mingled  anything  at  all  with 
necessity.  For  all  that  he  hath  written,  are  geometri- 
cal propositions,  which  are  without  comparison  of  any 
other  writings  whatsoever:  because  the  subject  where- 
of they  treat,  doth  appear  by  demonstration,  the 
maker  gives  them  the  grace  and  the  greatness,  and 
the  demonstration  proving  it  so  exquisitely,  with  won- 
derful reason  and  facility,  as  it  is  not  repugnable. 
For  in  all  geometry  are  not  to  be  found  more  pro- 
found and  difficult  matters  written,  in  more  plain 
and  simple  terms,  and  by  more  easy  principles,  than 
those  which  he  hath  invented.  Now  some  do  impute 
this,  to  the  sharpness  of  his  wit  and  understanding, 
which  was  a  natural  gift  in  him :  others  do  refer  it  to 
the  extreme  pains  he  took,  which  made  these  things 
come  so  easily  from  him,  that  they  seemed  as  if  they 
had  been  no  trouble  to  him  at  all.  For  no  man  living 
of  himself  can  devise  the  demonstration  of  his  propo- 
sitions, what  pains  soever  he  take  to  seek  it :  and  yet 
straight  so  soon  as  he  cometh  to  declare  and  open  it, 
every  man  then  imagineth  with  himself  he  could  have 
found  it  out  well  enough,  he  can  then  so  plainly  make 
demonstration  of  the  thing  he  meaneth  to  show.  And 
therefore  that  methinks  is  likely  to  be  true,  which  they 

204 


ALEXANDRIAN  OR  HELLENISTIC  PERIOD 

write  of  him :  that  he  was  so  ravished  and  drunk  with 
the  sweet  enticements  of  this  siren,  which  as  it  were 
lay  continually  with  him,  as  he  forgot  his  meat  and 
drink,  and  was  careless  otherwise  of  himself,  that  often- 
times his  servants  got  him  against  his  will  to  the  baths 
to  wash  and  anoint  him:  and  yet  being  there,  he  would 
ever  be  drawing  out  of  the  geometrical  figures,  even  in 
the  very  imbers  of  the  chimney.  And  while  they  were 
anointing  of  him  with  oils  and  sweet  savours,  with  his 
finger  he  did  draw  lines  upon  his  naked  body:  so  far 
was  he  taken  from  himself,  and  brought  into  an  ec- 
stasy or  trance,  with  the  delight  he  had  in  the  study  of 
geometry,  and  truly  ravished  with  the  love  of  the 
Muses.  But  amongst  many  notable  things  he  devised, 
it  appeareth,  that  he  most  esteemed  the  demonstration 
of  the  proportion  between  the  cylinder  (to  wit,  the 
round  column)  and  the  sphere  or  globe  contained  in 
the  same :  for  he  prayed  his  kinsmen  and  friends,  that 
after  his  death  they  would  put  a  cylinder  upon  his 
tomb,  containing  a  massy  sphere,  with  an  inscription  of 
the  proportion,  whereof  the  continent  exceedeth  the 
thing  contained."  2 

It  should  be  observed  that  neither  Polybius  nor 
Plutarch  mentions  the  use  of  burning-glasses  in  con- 
nection with  the  siege  of  Syracuse,  nor  indeed  are  these 
referred  to  by  any  other  ancient  writer  of  authority. 
Nevertheless,  a  story  gained  credence  down  to  a  late 
day  to  the  effect  that  Archimedes  had  set  fire  to  the 
fleet  of  the  enemy  with  the  aid  of  concave  mirrors. 
An  experiment  was  made  by  Sir  Isaac  Newton  to  show 
the  possibility  of  a  phenomenon  so  well  in  accord 
with  the  genius  of  Archimedes,  but  the  silence  of  all 

205 


A   HISTORY   OF  SCIENCE 

the  early  authorities  makes  it  more  than  doubtful 
whether  any  such  expedient  was  really  adopted. 

It  will  be  observed  that  the  chief  principle  involved 
in  all  these  mechanisms  was  a  capacity  to  transmit 
great  power  through  levers  and  pulleys,  and  this  brings 
us  to  the  most  important  field  of  the  Syracusan  phi- 
losopher's activity.  It  was  as  a  student  of  the  lever 
and  the  pulley  that  Archimedes  was  led  to  some  of  his 
greatest  mechanical  discoveries.  He  is  even  credited 
with  being  the  discoverer  of  the  compound  pulley. 
More  likely  he  was  its  developer  only,  since  the  prin- 
ciple of  the  pulley  was  known  to  the  old  Babylonians, 
as  their  sculptures  testify.  But  there  is  no  reason  to 
doubt  the  general  outlines  of  the  story  that  Archi- 
medes astounded  King  Hiero  by  proving  that,  with  the 
aid  of  multiple  pulleys,  the  strength  of  one  man  could 
suffice  to  drag  the  largest  ship  from  its  moorings. 

The  property  of  the  lever,  from  its  fundamental 
principle,  was  studied  by  him,  beginning  with  the  self- 
evident  fact  that  "  equal  bodies  at  the  ends  of  the  equal 
arms  of  a  rod,  supported  on  its  middle  point,  will  bal- 
ance each  other" ;  or,  what  amounts  to  the  same  thing 
stated  in  another  way,  a  regular  cylinder  of  uniform 
matter  will  balance  at  its  middle  point.  From  this 
starting-point  he  elaborated  the  subject  on  such  clear 
and  satisfactory  principles  that  they  stand  to-day 
practically  unchanged  and  with  few  additions.  From 
all  his  studies  and  experiments  he  finally  formulated 
the  principle  that  "bodies  will  be  in  equilibrio  when 
their  distance  from  the  fulcrum  or  point  of  support  is 
inversely  as  their  weight."  He  is  credited  with  hav- 
ing summed  up  his  estimate  of  the  capabilities  of  the 

206 


ALEXANDRIAN  OR  HELLENISTIC  PERIOD 

lever  with  the  well-known  expression,  "  Give  me  a  ful- 
crum on  which  to  rest  or  a  place  on  which  to  stand, 
and  I  will  move  the  earth." 

But  perhaps  the  feat  of  all  others  that  most  appealed 
to  the  imagination  of  his  contemporaries,  and  possibly 
also  the  one  that  had  the  greatest  bearing  upon  the 
position  of  Archimedes  as  a  scientific  discoverer,  was 
the  one  made  familiar  through  the  tale  of  the  crown  of 
Hiero.  This  crown,  so  the  story  goes,  was  supposed 
to  be  made  of  solid  gold,  but  King  Hiero  for  some  rea- 
son suspected  the  honesty  of  the  jeweller,  and  desired 
to  know  if  Archimedes  could  devise  a  way  of  testing 
the  question  without  injuring  the  crown.  Greek  im- 
agination seldom  spoiled  a  story  in  the  telling,  and 
in  this  case  the  tale  was  allowed  to  take  on  the  most 
picturesque  of  phases.  The  philosopher,  we  are  as- 
sured, pondered  the  problem  for  a  long  time  without 
succeeding,  but  one  day  as  he  stepped  into  a  bath,  his 
attention  was  attracted  by  the  overflow  of  water.  A 
new  train  of  ideas  was  started  in  his  ever-receptive 
brain.  Wild  with  enthusiasm  he  sprang  from  the 
bath,  and,  forgetting  his  robe,  dashed  along  the  streets 
of  Syracuse,  shouting:  "Eureka!  Eureka!"  (I  have 
found  it !)  The  thought  that  had  come  into  his  mind 
was  this :  That  any  heavy  substance  must  have  a  bulk 
proportionate  to  its  weight ;  that  gold  and  silver  differ 
in  weight,  bulk  for  bulk,  and  that  the  way  to  test  the 
bulk  of  such  an  irregular  object  as  a  crown  was  to  im- 
merse it  in  water.  The  experiment  was  made.  A 
lump  of  pure  gold  of  the  weight  of  the  crown  was  im- 
mersed in  a  certain  receptacle  filled  with  water,  and 
the  overflow  noted.    Then  a  lump  of  pure  silver  of  the 

207 


A   HISTORY   OF  SCIENCE 

same  weight  was  similarly  immersed ;  lastly  the  crown 
itself  was  immersed,  and  of  course — for  the  story  must 
not  lack  its  dramatic  sequel — was  found  bulkier  than 
its  weight  of  pure  gold.  Thus  the  genius  that  could 
balk  warriors  and  armies  could  also  foil  the  wiles  of 
the  silversmith. 

Whatever  the  truth  of  this  picturesque  narrative, 
the  fact  remains  that  some  such  experiments  as  these 
must  have  paved  the  way  for  perhaps  the  greatest  of 
all  the  studies  of  Archimedes — those  that  relate  to  the 
buoyancy  of  water.  Leaving  the  field  of  fable,  we 
must  now  examine  these  with  some  precision.  Fort- 
unately, the  writings  of  Archimedes  himself  are  still 
extant,  in  which  the  results  of  his  remarkable  experi- 
ments are  related,  so  we  may  present  the  results  in  the 
words  of  the  discoverer. 

Here  they  are :  "  First:  The  surface  of  every  coherent 
liquid  in  a  state  of  rest  is  spherical,  and  the  centre 
of  the  sphere  coincides  with  the  centre  of  the  earth. 
Second:  A  solid  body  which,  bulk  for  bulk,  is  of  the 
same  weight  as  a  liquid,  if  immersed  in  the  liquid  will 
sink  so  that  the  surface  of  the  body  is  even  with  the 
surface  of  the  liquid,  but  will  not  sink  deeper.  Third : 
Any  solid  body  which  is  lighter,  bulk  for  bulk,  than  a 
liquid,  if  placed  in  the  liquid  will  sink  so  deep  as  to 
displace  the  mass  of  liquid  equal  in  weight  to  another 
body.  Fourth:  If  a  body  which  is  lighter  than  a 
liquid  is  forcibly  immersed  in  the  liquid,  it  will  be 
pressed  upward  with  a  force  corresponding  to  the 
weight  of  a  like  volume  of  water,  less  the  weight  of  the 
body  itself.  Fifth :  Solid  bodies  which,  bulk  for  bulk, 
are  heavier  than  a  liquid,  when  immersed  in  the  liquid 

208 


ALEXANDRIAN  OR  HELLENISTIC  PERIOD 

sink  to  the  bottom,  but  become  in  the  liquid  as  much 
lighter  as  the  weight  of  the  displaced  water  itself  dif- 
fers from  the  weight  of  the  solid."  These  propositions 
are  not  difficult  to  demonstrate,  once  they  are  con- 
ceived, but  their  discovery,  combined  with  the  dis- 
covery of  the  laws  of  statics  already  referred  to,  may 
justly  be  considered  as  proving  Archimedes  the  most 
inventive  experimenter  of  antiquity. 

Curiously  enough,  the  discovery  which  Archimedes 
himself  is  said  to  have  considered  the  most  important 
of  all  his  innovations  is  one  that  seems  much  less  strik- 
ing. It  is  the  answer  to  the  question,  What  is  the  re- 
lation in  bulk  between  a  sphere  and  its  circumscribing 
cylinder?  Archimedes  finds  that  the  ratio  is  simply 
two  to  three.  We  are  not  informed  as  to  how  he  reach- 
ed his  conclusion,  but  an  obvious  method  would  be  to 
immerse  a  ball  in  a  cylindrical  cup.  The  experiment 
is  one  which  any  one  can  make  for  himself,  with  ap- 
proximate accuracy,  with  the  aid  of  a  tumbler  and  a 
solid  rubber  ball  or  a  billiard-ball  of  just  the  right  size. 
Another  geometrical  problem  which  Archimedes  solved 
was  the  problem  as  to  the  size  of  a  triangle  which  has 
equal  area  with  a  circle;  the  answer  being,  a  triangle 
having  for  its  base  the  circumference  of  the  circle  and 
for  its  altitude  the  radius.  Archimedes  solved  also 
the  problem  of  the  relation  of  the  diameter  of  the  circle 
to  its  circumference;  his  answer  being  a  close  ap- 
proximation to  the  familiar  3. 141 6,  which  every  tyro 
in  geometry  will  recall  as  the  equivalent  of  tt. 

Numerous  other  of  the  studies  of  Archimedes  having 
reference  to  conic  sections,  properties  of  curves  and 
spirals,  and  the  like,  are  too  technical  to  be  detailed 

VOL.  I. — 14  209 


A   HISTORY   OF   SCIENCE 

here.  The  extent  of  his  mathematical  knowledge, 
however,  is  suggested  by  the  fact  that  he  computed 
in  great  detail  the  number  of  grains  of  sand  that  would 
be  required  to  cover  the  sphere  of  the  sun's  orbit, 
making  certain  hypothetical  assumptions  as  to  the 
size  of  the  earth  and  the  distance  of  the  sun  for  the 
purposes  of  argument.  Mathematicians  find  his  com- 
putation peculiarly  interesting  because  it  evidences 
a  crude  conception  of  the  idea  of  logarithms.  From 
our  present  stand-point,  the  paper  in  which  this  calcu- 
lation is  contained  has  considerable  interest  because 
of  its  assumptions  as  to  celestial  mechanics.  Thus 
Archimedes  starts  out  with  the  preliminary  assump- 
tion that  the  circumference  of  the  earth  is  less  than 
three  million  stadia.  It  must  be  understood  that  this 
assumption  is  purely  for  the  sake  of  argument.  Ar- 
chimedes expressly  states  that  he  takes  this  number 
because  it  is  "ten  times  as  large  as  the  earth  has 
been  supposed  to  be  by  certain  investigators."  Here, 
perhaps,  the  reference  is  to  Eratosthenes,  whose  meas- 
urement of  the  earth  we  shall  have  occasion  to  re- 
vert to  in  a  moment.  Continuing,  Archimedes  as- 
serts that  the  sun  is  larger  than  the  earth,  and  the 
earth  larger  than  the  moon.  In  this  assumption,  he 
says,  he  is  following  the  opinion  of  the  majority  of 
astronomers.  In  the  third  place,  Archimedes  assumes 
that  the  diameter  of  the  sun  is  not  more  than  thirty 
times  greater  than  that  of  the  moon.  Here  he  is  prob- 
ably basing  his  argument  upon  another  set  of  measure- 
ments of  Aristarchus,  to  which,  also,  we  shall  presently 
refer  more  at  length.  In  reality,  his  assumption  is  very 
far  from  the  truth,  since  the  actual  diameter  of  the 

210 


ALEXANDRIAN  OR  HELLENISTIC  PERIOD 

sun,  as  we  now  know,  is  something  like  four  hundred 
times  that  of  the  moon.  Fourth,  the  circumference 
of  the  sun  is  greater  than  one  side  of  the  thousand- 
faced  figure  inscribed  in  its  orbit.  The  measure- 
ment, it  is  expressly  stated,  is  based  on  the  measure- 
ments of  Aristarchus,  who  makes  the  diameter  of  the 
sun  yl-Q  of  its  orbit.  Archimedes  adds,  however,  that 
he  himself  has  measured  the  angle  and  that  it  appears 
to  him  to  be  less  than  y^,  and  greater  than  ^-i-g  part  of 
the  orbit.  That  is  to  say,  reduced  to  modern  termi- 
nology, he  places  the  limit  of  the  sun's  apparent  size 
between  thirty-three  minutes  and  twenty-seven  min- 
utes of  arc.  As  the  real  diameter  is  thirty-two  min- 
utes, this  calculation  is  surprisingly  exact,  considering 
the  implements  then  at  command.  But  the  honor  of 
first  making  it  must  be  given  to  Aristarchus  and  not  to 
Archimedes. 

We  need  not  follow  Archimedes  to  the  limits  of  his 
incomprehensible  numbers  of  sand-grains.  The  calcu- 
lation is  chiefly  remarkable  because  it  was  made  be- 
fore the  introduction  of  the  so-called  Arabic  numerals 
had  simplified  mathematical  calculations.  It  will  be 
recalled  that  the  Greeks  used  letters  for  numerals, 
and,  having  no  cipher,  they  soon  found  themselves  in 
difficulties  when  large  numbers  were  involved.  The 
Roman  system  of  numerals  simplified  the  matter 
somewhat,  but  the  beautiful  simplicity  of  the  decimal 
system  did  not  come  into  vogue  until  the  Middle  Ages, 
as  we  shall  see.  Notwithstanding  the  difficulties, 
however,  Archimedes  followed  out  his  calculations 
to  the  piling  up  of  bewildering  numbers,  which 
the    modern    mathematician   finds    to    be    the    con- 

211 


A    HISTORY    OF   SCIENCE 

sistent   outcome   of   the   problem   he   had   set    him- 
self. 

But  it  remains  to  notice  the  most  interesting  feature 
of  this  document  in  which  the  calculation  of  the  sand- 
grains  is  contained.  "It  was  known  to  me,"  says 
Archimedes,  "that  most  astronomers  understand  by 
the  expression  '  world '  (universe)  a  ball  of  which  the 
centre  is  the  middle  point  of  the  earth,  and  of  which 
the  radius  is  a  straight  line  between  the  centre  of  the 
earth  and  the  sun."  Archimedes  himself  appears  to 
accept  this  opinion  of  the  majority, — it  at  least  serves 
as  well  as  the  contrary  hypothesis  for  the  purpose  of 
his  calculation, — but  he  goes  on  to  say:  "Aristar- 
chus  of  Samos,  in  his  writing  against  the  astronomers, 
seeks  to  establish  the  fact  that  the  world  is  really  very 
different  from  this.  He  holds  the  opinion  that  the  fixed 
stars  and  the  sun  are  immovable  and  that  the  earth  re- 
volves in  a  circular  line  about  the  sun,  the  sun  being 
at  the  centre  of  this  circle."  This  remarkable  bit  of 
testimony  establishes  beyond  question  the  position 
of  Aristarchus  of  Samos  as  the  Copernicus  of  antiquity. 
We  must  make  further  inquiry  as  to  the  teachings  of 
the  man  who  had  gained  such  a  remarkable  insight 
into  the  true  system  of  the  heavens. 

ARISTARCHUS  OF  SAMOS,  THE  COPERNICUS  OF  ANTIQUITY 

It  appears  that  Aristarchus  was  a  contemporary  of 
Archimedes,  but  the  exact  dates  of  his  life  are  not 
known.  He  was  actively  engaged  in  making  astro- 
nomical observations  in  Samos  somewhat  before  the 
middle  of  the  third  century  b.c  ;  in  other  words,  just 
at  the  time  when  the  activities  of  the  Alexandrian 

212 


ALEXANDRIAN  OR  HELLENISTIC  PERIOD 

school  were  at  their  height.  Hipparchus,  at  a  later 
day,  was  enabled  to  compare  his  own  observations 
with  those  made  by  Aristarchus,  and,  as  we  have  just 
seen,  his  work  was  well  known  to  so  distant  a  contem- 
porary as  Archimedes.  Yet  the  facts  of  his  life  are 
almost  a  blank  for  us,  and  of  his  writings  only  a  single 
one  has  been  preserved.  That  one,  however,  is  a  most 
important  and  interesting  paper  on  the  measurements 
of  the  sun  and  the  moon.  Unfortunately,  this  paper 
gives  us  no  direct  clew  as  to  the  opinions  of  Aristarchus 
concerning  the  relative  positions  of  the  earth  and  sun. 
But  the  testimony  of  Archimedes  as  to  this  is  unequiv- 
ocal, and  this  testimony  is  supported  by  other  rumors 
in  themselves  less  authoritative. 

In  contemplating  this  astronomer  of  Samos,  then, 
we  are  in  the  presence  of  a  man  who  had  solved  in  its 
essentials  the  problem  of  the  mechanism  of  the  solar 
system.  It  appears  from  the  words  of  Archimedes  that 
Aristarchus  had  propounded  his  theory  in  explicit 
writings.  Unquestionably,  then,  he  held  to  it  as  a  posi- 
tive doctrine,  not  as  a  mere  vague  guess.  We  shall 
show,  in  a  moment,  on  what  grounds  he  based  his 
opinion.  Had  his  teaching  found  vogue,  the  story  of 
science  would  be  very  different  from  what  it  is.  We 
should  then  have  no  tale  to  tell  of  a  Copernicus  coming 
upon  the  scene  fully  seventeen  hundred  years  later 
with  the  revolutionary  doctrine  that  our  world  is  not 
the  centre  of  the  universe.  We  should  not  have  to 
tell  of  the  persecution  of  a  Bruno  or  of  a  Galileo  for 
teaching  this  doctrine  in  the  seventeenth  century  of  an 
era  which  did  not  begin  till  two  hundred  years  after 
the  death  of  Aristarchus.     But,  as  we  know,  the  teach- 

213 


A   HISTORY   OF   SCIENCE 

ing  of  the  astronomer  of  Samos  did  not  win  its  way. 
The  old  conservative  geocentric  doctrine,  seemingly 
so  much  more  in  accordance  with  the  every-day  ob- 
servations of  mankind,  supported  by  the  majority  of 
astronomers  with  the  Peripatetic  philosophers  at  their 
head,  held  its  place.  It  found  fresh  supporters  pres- 
ently among  the  later  Alexandrians,  and  so  fully 
eclipsed  the  heliocentric  view  that  we  should  scarcely 
know  that  view  had  even  found  an  advocate  were  it 
not  for  here  and  there  such  a  chance  record  as  the 
phrases  we  have  just  quoted  from  Archimedes.  Yet, 
as  we  now  see,  the  heliocentric  doctrine,  which  we  know 
to  be  true,  had  been  thought  out  and  advocated  as  the 
correct  theory  of  celestial  mechanics  by  at  least  one 
worker  of  the  third  century  B.C.  Such  an  idea,  we 
may  be  sure,  did  not  spring  into  the  mind  of  its 
originator  except  as  the  culmination  of  a  long  series  of 
observations  and  inferences.  The  precise  character 
of  the  evolution  we  perhaps  cannot  trace,  but  its 
broader  outlines  are  open  to  our  observation,  and  we 
may  not  leave  so  important  a  topic  without  at  least 
briefly  noting  them. 

Fully  to  understand  the  theory  of  Aristarchus,  we 
must  go  back  a  century  or  two  and  recall  that  as  long 
ago  as  the  time  of  that  other  great  native  of  Samos, 
Pythagoras,  the  conception  had  been  reached  that  the 
earth  is  in  motion.  We  saw,  in  dealing  with  Pythag- 
oras, that  we  could  not  be  sure  as  to  precisely  what  he 
himself  taught,  but  there  is  no  question  that  the  idea 
of  the  world's  motion  became  from  an  early  day  a  so- 
called  Pythagorean  doctrine.  While  all  the  other 
philosophers,  so  far  as  we  know,  still  believed  that  the 

214 


ALEXANDRIAN  OR  HELLENISTIC  PERIOD 

world  was  flat,  the  Pythagoreans  out  in  Italy  taught 
that  the  world  is  a  sphere  and  that  the  apparent  mo- 
tions of  the  heavenly  bodies  are  really  due  to  the  actual 
motion  of  the  earth  itself.  They  did  not,  however, 
vault  to  the  conclusion  that  this  true  motion  of  the 
earth  takes  place  in  the  form  of  a  circuit  about  the 
sun.  Instead  of  that,  they  conceived  the  central  body 
of  the  universe  to  be  a  great  fire,  invisible  from  the 
earth,  because  the  inhabited  side  of  the  terrestrial 
ball  was  turned  awa}r  from  it.  The  sun,  it  was  held, 
is  but  a  great  mirror,  which  reflects  the  light  from  the 
central  fire.  Sun  and  earth  alike  revolve  about  this 
great  fire,  each  in  its  own  orbit.  Between  the  earth 
and  the  central  fire  there  was,  curiously  enough,  sup- 
posed to  be  an  invisible  earthlike  body  which  was  given 
the  name  of  Anticthon,  or  counter-earth.  This  body, 
itself  revolving  about  the  central  fire,  was  supposed  to 
shut  off  the  central  light  now  and  again  from  the  sun 
or  from  the  moon,  and  thus  to  account  for  certain 
eclipses  for  which  the  shadow  of  the  earth  did  not 
seem  responsible.  It  was,  perhaps,  largely  to  account 
for  such  eclipses  that  the  counter-earth  was  invented. 
But  it  is  supposed  that  there  was  another  reason.  The 
Pythagoreans  held  that  there  is  a  peculiar  sacredness 
in  the  number  ten.  Just  as  the  Babylonians  of 
the  early  day  and  the  Hegelian  philosophers  of  a 
more  recent  epoch  saw  a  sacred  connection  between 
the  number  seven  and  the  number  of  planetary 
bodies,  so  the  Pythagoreans  thought  that  the  uni- 
verse must  be  arranged  in  accordance  with  the  num- 
ber ten.  Their  count  of  the  heavenly  bodies,  includ- 
ing the   sphere   of  the  fixed  stars,  seemed  to  show 

215 


A   HISTORY   OF   SCIENCE 

nine,  and  the  counter  -  earth  supplied  the  missing 
body. 

The  precise  genesis  and  development  of  this  idea 
cannot  now  be  followed,  but  that  it  was  prevalent  about 
the  fifth  century  B.C.  as  a  Pythagorean  doctrine  can- 
not be  questioned.  Anaxagoras  also  is  said  to  have 
taken  account  of  the  hypothetical  counter-earth  in  his 
explanation  of  eclipses;  though,  as  we  have  seen,  he 
probably  did  not  accept  that  part  of  the  doctrine 
which  held  the  earth  to  be  a  sphere.  The  names  of 
Philolaus  and  Heraclides  have  been  linked  with  cer- 
tain of  these  Pythagorean  doctrines.  Eudoxus,  too, 
who,  like  the  others,  lived  in  Asia  Minor  in  the  fourth 
century  b.c,  was  held  to  have  made  special  studies  of 
the  heavenly  spheres  and  perhaps  to  have  taught  that 
the  earth  moves.  So,  too,  Nicetas  must  be  named 
among  those  whom  rumor  credited  with  having  taught 
that  the  world  is  in  motion.  In  a  word,  the  evidence, 
so  far  as  we  can  garner  it  from  the  remaining  frag- 
ments, tends  to  show  that  all  along,  from  the  time  of 
the  early  Pythagoreans,  there  had  been  an  under- 
current of  opinion  in  the  philosophical  world  which 
questioned  the  fixity  of  the  earth;  and  it  would  seem 
that  the  school  of  thinkers  who  tended  to  accept  the 
revolutionary  view  centred  in  Asia  Minor,  not  far  from 
the  early  home  of  the  founder  of  the  Pythagorean  doc- 
trines. It  was  not  strange,  then,  that  the  man  who 
was  finally  to  carry  these  new  opinions  to  their  logical 
conclusion  should  hail  from  Samos. 

But  what  was  the  support  which  observation  could 
give  to  this  new,  strange  conception  that  the  heavenly 
bodies  do  not  in  reality  move  as  they  seem  to  move, 

216 


ALEXANDRIAN  OR  HELLENISTIC  PERIOD 

but  that  their  apparent  motion  is  due  to  the  actual 
revolution  of  the  earth?  It  is  extremely  difficult  for 
any  one  nowadays  to  put  himself  in  a  mental  position 
to  answer  this  question.  We  are  so  accustomed  to 
conceive  the  solar  system  as  we  know  it  to  be,  that  we 
are  wont  to  forget  how  very  different  it  is  from  what  it 
seems.  Yet  one  needs  but  to  glance  up  at  the  sky,  and 
then  to  glance  about  one  at  the  solid  earth,  to  grant, 
on  a  moment's  reflection,  that  the  geocentric  idea  is  of 
all  others  the  most  natural ;  and  that  to  conceive  the 
sun  as  the  actual  centre  of  the  solar  system  is  an  idea 
which  must  look  for  support  to  some  other  evidence 
than  that  which  ordinary  observation  can  give.  Such 
was  the  view  of  most  of  the  ancient  philosophers,  and 
such  continued  to  be  the  opinion  of  the  majority  of 
mankind  long  after  the  time  of  Copernicus.  We  must 
not  forget  that  even  so  great  an  observing  astronomer 
as  Tycho  Brahe,  so  late  as  the  seventeenth  century, 
declined  to  accept  the  heliocentric  theory,  though  ad- 
mitting that  all  the  planets  except  the  earth  revolve 
about  the  sun.  We  shall  see  that  before  the  Alexan- 
drian school  lost  its  influence  a  geocentric  scheme  had 
been  evolved  which  fully  explained  all  the  apparent 
motions  of  the  heavenly  bodies.  All  this,  then,  makes 
us  but  wonder  the  more  that  the  genius  of  an  Aris- 
tarchus  could  give  precedence  to  scientific  induction  as 
against  the  seemingly  clear  evidence  of  the  senses. 

What,  then,  was  the  line  of  scientific  induction  that 
led  Aristarchus  to  this  wonderful  goal?  Fortunate- 
ly, we  are  able  to  answer  that  query,  at  least  in 
part.  Aristarchus  gained  his  evidence  through  some 
wonderful    measurements.     First,    he    measured    the 

217 


A   HISTORY   OF   SCIENCE 

disks  of  the  sun  and  the  moon.  This,  of  course,  could 
in  itself  give  him  no  clew  to  the  distance  of  these  bod- 
ies, and  therefore  no  clew  as  to  their  relative  size ;  but 
in  attempting  to  obtain  such  a  clew  he  hit  upon  a  won- 
derful yet  altogether  simple  experiment.  It  occurred 
to  him  that  when  the  moon  is  precisely  dichotomized — 
that  is  to  say,  precisely  at  the  half — the  line  of  vision 
from  the  earth  to  the  moon  must  be  precisely  at  right- 
angles  with  the  line  of  light  passing  from  the  sun  to 
the  moon.  At  this  moment,  then,  the  imaginary  lines 
joining  the  sun,  the  moon,  and  the  earth,  make  a  right- 
angle  triangle.  But  the  properties  of  the  right-angle 
triangle  had  long  been  studied  and  were  well  under- 
stood. One  acute  angle  of  such  a  triangle  determines 
the  figure  of  the  triangle  itself.  We  have  already  seen 
that  Thales,  the  very  earliest  of  the  Greek  philosophers, 
measured  the  distance  of  a  ship  at  sea  by  the  applica- 
tion of  this  principle.  Now  Aristarchus  sights  the 
sun  in  place  of  Thales'  ship,  and,  sighting  the  moon  at 
the  same  time,  measures  the  angle  and  establishes  the 
shape  of  his  right-angle  triangle.  This  does  not  tell 
him  the  distance  of  the  sun,  to  be  sure,  for  he  does  not 
know  the  length  of  his  base-line — that  is  to  say,  of  the 
line  between  the  moon  and  the  earth.  But  it  does  es- 
tablish the  relation  of  that  base-line  to  the  other  lines 
of  the  triangle ;  in  other  words,  it  tells  him  the  distance 
of  the  sun  in  terms  of  the  moon's  distance.  As  Aris- 
tarchus strikes  the  angle,  it  shows  that  the  sun  is 
eighteen  times  as  distant  as  the  moon.  Now,  by  com- 
paring the  apparent  size  of  the  sun  with  the  apparent 
size  of  the  moon — which,  as  we  have  seen,  Aristarchus 
has  already  measured — he  is  able  to  tell  us  that  the 

218 


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ALEXANDRIAN  OR  HELLENISTIC  PERIOD 

sun  is  "more  than  5832  times,  and  less  than  8000" 
times  larger  than  the  moon;  though  his  measure- 
ments, taken  by  themselves,  give  no  clew  to  the 
actual  bulk  of  either  body.  These  conclusions,  be 
it  understood,  are  absolutely  valid  inferences — nay, 
demonstrations — from  the  measurements  involved, 
provided  only  that  these  measurements  have  been 
correct.  Unfortunately,  the  angle  of  the  triangle 
we  have  just  seen  measured  is  exceedingly  difficult  to 
determine  with  accuracy,  while  at  the  same  time,  as  a 
moment's  reflection  will  show,  it  is  so  large  an  angle 
that  a  very  slight  deviation  from  the  truth  will  greatly 
affect  the  distance  at  which  its  line  joins  the  other  side 
of  the  triangle.  Then  again,  it  is  virtually  impossible 
to  tell  the  precise  moment  when  the  moon  is  at  half,  as 
the  line  it  gives  is  not  so  sharp  that  we  can  fix  it  with 
absolute  accuracy.  There  is,  moreover,  another  ele- 
ment of  error  due  to  the  refraction  of  light  by  the 
earth's  atmosphere.  The  experiment  was  probably 
made  when  the  sun  was  near  the  horizon,  at  which  time, 
as  we  now  know,  but  as  Aristarchus  probably  did  not 
suspect,  the  apparent  displacement  of  the  sun's  posi- 
tion is  considerable;  and  this  displacement,  it  will  be 
observed,  is  in  the  direction  to  lessen  the  angle  in 
question. 

In  point  of  fact,  Aristarchus  estimated  the  angle  at 
eighty-seven  degrees.  Had  his  instrument  been  more 
precise,  and  had  he  been  able  to  take  account  of  all  the 
elements  of  error,  he  would  have  found  it  eighty-seven 
degrees  and  fifty  -  two  minutes.  The  difference  of 
measurement  seems  slight;  but  it  sufficed  to  make  the 
computations  differ  absurdly  from  the  truth.     The 

219 


A   HISTORY   OF   SCIENCE 

sun  is  really  not  merely  eighteen  times  but  more  than 
two  hundred  times  the  distance  of  the  moon,  as  Wen- 
delein  discovered  on  repeating  the  experiment  of  Aris- 
tarchus  about  two  thousand  years  later.  Yet  this  dis- 
crepancy does  not  in  the  least  take  away  from  the 
validity  of  the  method  which  Aristarchus  employed. 
Moreover,  his  conclusion,  stated  in  general  terms, 
was  perfectly  correct:  the  sun  is  many  times  more 
distant  than  the  moon  and  vastly  larger  than  that 
body.  Granted,  then,  that  the  moon  is,  as  Aristarchus 
correctly  believed,  considerably  less  in  size  than  the 
earth,  the  sun  must  be  enormously  larger  than  the 
earth ;  and  this  is  the  vital  inference  which,  more  than 
any  other,  must  have  seemed  to  Aristarchus  to  con- 
firm the  suspicion  that  the  sun  and  not  the  earth  is  the 
centre  of  the  planetary  system.  It  seemed  to  him  in- 
herently improbable  that  an  enormously  large  body 
like  the  sun  should  revolve  about  a  small  one  such  as 
the  earth.  And  again,  it  seemed  inconceivable  that  a 
body  so  distant  as  the  sun  should  whirl  through  space 
so  rapidly  as  to  make  the  circuit  of  its  orbit  in  twenty- 
four  hours.  But,  on  the  other  hand,  that  a  small  body 
like  the  earth  should  revolve  about  the  gigantic  sun 
seemed  inherently  probable.  This  proposition  granted, 
the  rotation  of  the  earth  on  its  axis  follows  as  a  neces- 
sary consequence  in  explanation  of  the  seeming  mo- 
tion of  the  stars.  Here,  then,  was  the  heliocentric 
doctrine  reduced  to  a  virtual  demonstration  by  Aris- 
tarchus of  Samos,  somewhere  about  the  middle  of  the 
third  century  B.C. 

It  must  be  understood  that  in  following  out  the 
steps  of  reasoning  by  which  we  suppose  Aristarchus 

220 


ALEXANDRIAN  OR  HELLENISTIC  PERIOD 

to  have  reached  so  remarkable  a  conclusion,  we  have 
to  some  extent  guessed  at  the  processes  of  thought- 
development  ;  for  no  line  of  explication  written  by  the 
astronomer  himself  on  this  particular  point  has  come 
down  to  us.  There  does  exist,  however,  as  we  have 
already  stated,  a  very  remarkable  treatise  by  Aris- 
tarchus  on  the  Size  and  Distance  of  the  Sun  and  the 
Moon,  which  so  clearly  suggests  the  methods  of 
reasoning  of  the  great  astronomer,  and  so  explicitly 
cites  the  results  of  his  measurements,  that  we  cannot 
well  pass  it  by  without  quoting  from  it  at  some  length. 
It  is  certainly  one  of  the  most  remarkable  scientific 
documents  of  antiquity.  As  already  noted,  the 
heliocentric  doctrine  is  not  expressly  stated  here. 
It  seems  to  be  tacitly  implied  throughout,  but  it  is 
not  a  necessary  consequence  of  any  of  the  propositions 
expressly  stated.  These  propositions  have  to  do  with 
certain  observations  and  measurements  and  what 
Aristarchus  believes  to  be  inevitable  deductions  from 
them,  and  he  perhaps  did  not  wish  to  have  these 
deductions  challenged  through  associating  them  with 
a  theory  which  his  contemporaries  did  not  accept. 
In  a  word,  the  paper  of  Aristarchus  is  a  rigidly  scien- 
tific document  unvitiated  by  association  with  any 
theorizings  that  are  not  directly  germane  to  its  central 
theme.  The  treatise  opens  with  certain  hypotheses 
as  follows : 

"  First.  The  moon  receives  its  light  from  the  sun. 

"Second.  The  earth  may  be  considered  as  a  point 
and  as  the  centre  of  the  orbit  of  the  moon. 

"Third.  When  the  moon  appears  to  us  dichotomized 
it  offers  to  our  view  a  great  circle  [or  actual  meridian] 

221 


A   HISTORY   OF   SCIENCE 

of  its  circumference  which  divides  the  illuminated  part 
from  the  dark  part. 

"Fourth.  When  the  moon  appears  dichotomized  its 
distance  from  the  sun  is  less  than  a  quarter  01  the 
circumference  [of  its  orbit]  by  a  thirtieth  part  of  that 
quarter." 

That  is  to  say,  in  modern  terminology,  the  moon 
at  this  time  lacks  three  degrees  (one  thirtieth  of  ninety 
degrees)  of  being  at  right  angles  with  the  line  of  the 
sun  as  viewed  from  the  earth;  or,  stated  otherwise, 
the  angular  distance  of  the  moon  from  the  sun  as 
viewed  from  the  earth  is  at  this  time  eighty -seven 
degrees — this  being,  as  we  have  already  observed,  the 
fundamental  measurement  upon  which  so  much  de- 
pends. .  We  may  fairly  suppose  that  some  previous 
paper  of  Aristarchus's  has  detailed  the  measurement 
which  here  is  taken  for  granted,  yet  which  of  course 
could  depend  solely  on  observation. 

"Fifth.  The  diameter  of  the  shadow  [cast  by  the 
earth  at  the  point  where  the  moon's  orbit  cuts  that 
shadow  when  the  moon  is  eclipsed]  is  double  the 
diameter  of  the  moon." 

Here  again  a  knowledge  of  previously  established 
measurements  is  taken  for  granted ;  but,  indeed,  this  is 
the  case  throughout  the  treatise. 

"  Sixth.  The  arc  subtended  in  the  sky  by  the  moon 
is  a  fifteenth  part  of  a  sign"  of  the  zodiac;  that  is 
to  say,  since  there  are  twenty-four,  signs  in  the  zodiac, 
one-fifteenth  of  one  twenty-fourth,  or  in  modern  termi- 
nology, one  degree  of  arc.  This  is  Aristarchus's  meas- 
urement of  the  moon  to  which  we  have  already  referred 
when  speaking  of  the  measurements  of  Archimedes, 

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ALEXANDRIAN  OR  HELLENISTIC  PERIOD 

"If  we  admit  these  six  hypotheses,"  Aristarchus 
continues,  "it  follows  that  the  sun  is  more  than 
eighteen  times  more  distant  from  the  earth  than  is  the 
moon,  and  that  it  is  less  than  twenty  times  more 
distant,  and  that  the  diameter  of  the  sun  bears  a 
corresponding  relation  to  the  diameter  of  the  moon; 
which  is  proved  by  the  position  of  the  moon  when 
dichotomized.  But  the  ratio  of  the  diameter  of  the 
sun  to  that  of  the  earth  is  greater  than  nineteen  to 
three  and  less  than  forty-three  to  six.  This  is  demon- 
strated by  the  relation  of  the  distances,  by  the  position 
[of  the  moon]  in  relation  to  the  earth's  shadow,  and  by 
the  fact  that  the  arc  subtended  by  the  moon  is  a 
fifteenth  part  of  a  sign." 

Aristarchus  follows  with  nineteen  propositions  in- 
tended to  elucidate  his  hypotheses  and  to  demon- 
strate his  various  contentions.  These  show  a  singularly 
clear  grasp  of  geometrical  problems  and  an  altogether 
correct  conception  of  the  general  relations  as  to  size 
and  position  of  the  earth,  the  moon,  and  the  sun. 
His  reasoning  has  to  do  largely  with  the  shadow  cast 
by  the  earth  and  by  the  moon,  and  it  presupposes  a 
considerable  knowledge  of  the  phenomena  of  eclipses. 
His  first  proposition  is  that  "  two  equal  spheres  may 
always  be  circumscribed  in  a  cylinder;  two  unequal 
spheres  in  a  cone  of  which  the  apex  is  found  on  the 
side  of  the  smaller  sphere;  and  a  straight  line  joining 
the  centres  of  these  spheres  is  perpendicular  to  each 
of  the  two  circles  made  by  the  contact  of  the  surface 
of  the  cylinder  or  of  the  cone  with  the  spheres." 

It  will  be  observed  that  Aristarchus  has  in  mind  here 
the  moon,  the  earth,  and  the  sun  as  spheres  to  be 

223 


A   HISTORY    OF   SCIENCE 

circumscribed  within  a  cone,  which  cone  is  made 
tangible  and  measurable  by  the  shadows  cast  by 
the  non-luminous  bodies ;  since,  continuing,  he  clearly 
states  in  proposition  nine,  that  "when  the  sun  is 
totally  eclipsed,  an  observer  on  the  earth's  surface  is 
at  an  apex  of  a  cone  comprising  the  moon  and  the 
sun."  Various  propositions  deal  with  other  relations 
of  the  shadows  which  need  not  detain  us  since  they 
are  not  fundamentally  important,  and  we  may  pass 
to  the  final  conclusions  of  Aristarchus,  as  reached  in 
his  propositions  ten  to  nineteen. 

Now,  since  (proposition  ten)  "the  diameter  of  the 
sun  is  more  than  eighteen  times  and  less  than  twenty 
times  greater  than  that  of  the  moon,"  it  follows 
(proposition  eleven)  "that  the  bulk  of  the  sun  is  to 
that  of  the  moon  in  ratio,  greater  than  5832  to  1,  and 
less  than  8000  to  1." 

"Proposition  sixteen.  The  diameter  of  the  sun  is 
to  the  diameter  of  the  earth  in  greater  proportion  than 
nineteen  to  three,  and  less  than  forty-three  to  six. 

"  Proposition  seventeen.  The  bulk  of  the  sun  is  to 
that  of  the  earth  in  greater  proportion  than  6859  to 
27,  and  less  than  79,507  to  216. 

"Proposition  eighteen.  The  diameter  of  the  earth 
is  to  the  diameter  of  the  moon  in  greater  proportion 
than  108  to  43  and  less  than  60  to  19. 

"  Proposition  nineteen.  The  bulk  of  the  earth  is  to 
that  of  the  moon  in  greater  proportion  than  1,259,712 
to  79,507  and  less  than  216,000  to  6859." 

Such  then  are  the  more  important  conclusions  of 
this  very  remarkable  paper — a  paper  which  seems  to 
have  interest  to  the  successors  of  Aristarchus  genera- 

224 


ALEXANDRIAN  OR  HELLENISTIC  PERIOD 

tion  after  generation,  since  this  alone  of  all  the  writ- 
ings of  the  great  astronomer  has  been  preserved. 
How  widely  the  exact  results  of  the  measurements  of 
Aristarchus  differ  from  the  truth,  we  have  pointed 
out  as  we  progressed.  But  let  it  be  repeated  that  this 
detracts  little  from  the  credit  of  the  astronomer  who 
had  such  clear  and  correct  conceptions  of  the  relations 
of  the  heavenly  bodies  and  who  invented  such  correct 
methods  of  measurement.  Let  it  be  particularly 
observed,  however,  that  all  the  conclusions  of  Aris- 
tarchus are  stated  in  relative  terms.  He  nowhere 
attempts  to  estimate  the  precise  size  of  the  earth,  of 
the  moon,  or  of  the  sun,  or  the  actual  distance  of  one 
of  .these  bodies  from  another.  The  obvious  reason 
for  this  is  that  no  data  were  at  hand  from  which  to 
make  such  precise  measurements.  Had  Aristarchus 
known  the  size  of  any  one  of  the  bodies  in  question,  he 
might  readily,  of  course,  have  determined  the  size  of 
the  others  by  the  mere  application  of  his  relative 
scale;  but  he  had  no  means  of  determining  the  size 
of  the  earth,  and  to  this  extent  his  system  of  measure- 
ments remained  imperfect.  Where  Aristarchus  halted, 
however,  another  worker  of  the  same  period  took  the 
task  in  hand  and  by  an  altogether  wonderful  measure- 
ment determined  the  size  of  the  earth,  and  thus  brought 
the  scientific  theories  of  cosmology  to  their  climax. 
This  worthy  supplementor  of  the  work  of  Aristarchus 
was  Eratosthenes  of  Alexandria. 

ERATOSTHENES,   "  THE  SURVEYOR  OF  THE  WORLD" 

An  altogether  remarkable  man  was  this  native  of 
Cyrene,  who  came  to  Alexandria  from  Athens  to  be 

VOL.1.— IS  2  25 


A   HISTORY    OF   SCIENCE 

the  chief  librarian  of  Ptolemy  Euergetes.  He  was  not 
merely  an  astronomer  and  a  geographer,  but  a  poet  and 
grammarian  as  well.  His  contemporaries  jestingly 
called  him  Beta  the  Second,  because  he  was  said 
through  the  universality  of  his  attainments  to  be  "a 
second  Plato"  in  philosophy,  "a  second  Thales"  in 
astronomy,  and  so  on  throughout  the  list.  He  was  also 
called  the  "surveyor  of  the  world,"  in  recognition  of  his 
services  to  geography.  Hipparchus  said  of  him,  per- 
haps half  jestingly,  that  he  had  studied  astronomy  as 
a  geographer  and  geography  as  an  astronomer.  It  is 
not  quite  clear  whether  the  epigram  was  meant  as 
compliment  or  as  criticism.  Similar  phrases  have  been 
turned  against  men  of  versatile  talent  in  every  age. 
Be  that  as  it  may,  Eratosthenes  passed  into  history 
as  the  father  of  scientific  geography  and  of  scientific 
chronology ;  as  the  astronomer  who  first  measured  the 
obliquity  of  the  ecliptic ;  and  as  the  inventive  genius 
who  performed  the  astounding  feat  of  measuring  the 
size  of  the  globe  on  which  we  live  at  a  time  when 
only  a  relatively  small  portion  of  that  globe's  surface 
was  known  to  civilized  man.  It  is  no  discredit  to  ap- 
proach astronomy  as  a  geographer  and  geography  as  an 
astonomer  if  the  results  are  such  as  these.  What  Era- 
tosthenes really  did  was  to  approach  both  astronomy 
and  geography  from  two  seemingly  divergent  points 
of  attack — namely,  from  the  stand-point  of  the  geom- 
eter and  also  from  that  of  the  poet.  Perhaps  no  man 
in  any  age  has  brought  a  better  combination  of  ob- 
serving and  imaginative  faculties  to  the  aid  of  science. 
Nearly  all  the  discoveries  of  Eratosthenes  are  asso- 
ciated with  observations  of  the  shadows  cast  by  the 

226 


ALEXANDRIAN  OR  HELLENISTIC  PERIOD 

sun.  We  have  seen  that,  in  the  study  of  the  heavenly- 
bodies,  much  depends  on  the  measurement  of  angles. 
Now  the  easiest  way  in  which  angles  can  be  meas- 
ured, when  solar  angles  are  in  question,  is  to  pay  atten- 
tion, not  to  the  sun  itself,  but  to  the  shadow  that  it 
casts.  We  saw  that  Thales  made  some  remarkable 
measurements  with  the  aid  of  shadows,  and  we  have 
more  than  once  referred  to  the  gnomon,  which  is  the 
most  primitive,  but  which  long  remained  the  most  im- 
portant, of  astronomical  instruments.  It  is  believed 
that  Eratosthenes  invented  an  important  modifica- 
tion of  the  gnomon  which  was  elaborated  afterwards 
by  Hipparchus  and  called  an  armillary  sphere.  This 
consists  essentially  of  a  small  gnomon,  or  perpendicular 
post,  attached  to  a  plane  representing  the  earth's 
equator  and  a  hemisphere  in  imitation  of  the  earth's 
surface.  With  the  aid  of  this,  the  shadow  cast  by  the 
sun  could  be  very  accurately  measured.  It  involves 
no  new  principle.  Every  perpendicular  post  or  ob- 
ject of  any  kind  placed  in  the  sunlight  casts  a  shadow 
from  which  the  angles  now  in  question  could  be  roughly 
measured.  The  province  of  the  armillary  sphere  was 
to  make  these  measurements  extremely  accurate. 

With  the  aid  of  this  implement,  Eratosthenes  care- 
fully noted  the  longest  and  the  shortest  shadows  cast 
by  the  gnomon — that  is  to  say,  the  shadows  cast  on  the 
days  of  the  solstices.  He  found  that  the  distance  be- 
tween the  tropics  thus  measured  represented  470  42'  39" 
of  arc.  One-half  of  this,  or  230  51'  19.5",  represented 
the  obliquity  of  the  ecliptic — that  is  to  say,  the  angle 
by  which  the  earth's  axis  dipped  from  the  perpendicu- 
lar with  reference  to  its  orbit.     This  was  a  most  im- 

227 


A    HISTORY    OF    SCIENCE 

portant  observation,  and  because  of  its  accuracy  it  has 
served  modern  astronomers  well  for  comparison  in 
measuring  the  trifling  change  due  to  our  earth's  slow, 
swinging  wobble.  For  the  earth,  be  it  understood, 
like  a  great  top  spinning  through  space,  holds  its  po- 
sition with  relative  but  not  quite  absolute  fixity. 
It  must  not  be  supposed,  however,  that  the  experi- 
ment in  question  was  quite  new  with  Eratosthenes. 
His  merit  consists  rather  in  the  accuracy  with  which 
he  made  his  observation  than  in  the  novelty  of  the 
conception ;  for  it  is  recorded  that  Eudoxus,  a  full  cen- 
tury earlier,  had  remarked  the  obliquity  of  the  ecliptic. 
That  observer  had  said  that  the  obliquity  corresponded 
to  the  side  of  a  pentadecagon,  or  fifteen-sided  figure, 
which  is  equivalent  in  modern  phraseology  to  twenty- 
four  degrees  of  arc.  But  so  little  is  known  regarding 
the  way  in  which  Eudoxus  reached  his  estimate  that 
the  measurement  of  Eratosthenes  is  usually  spoken  of 
as  if  it  were  the  first  effort  of  the  kind. 

Much  more  striking,  at  least  in  its  appeal  to  the  pop- 
ular imagination,  was  that  other  great  feat  which 
Eratosthenes  performed  with  the  aid  of  his  perfected 
gnomon — the  measurement  of  the  earth  itself.  When 
we  reflect  that  at  this  period  the  portion  of  the  earth 
open  to  observation  extended  only  from  the  Straits 
of  Gibraltar  on  the  west  to  India  on  the  east,  and  from 
the  North  Sea  to  Upper  Egypt,  it  certainly  seems  enig- 
matical— at  first  thought  almost  miraculous — that  an 
observer  should  have  been  able  to  measure  the  entire 
globe.  That  he  should  have  accomplished  this  through 
observation  of  nothing  more  than  a  tiny  bit  of  Egyp- 
tian territory  and  a  glimpse  of  the  sun's  shadow  makes 

228 


ALEXANDRIAN  OR  HELLENISTIC  PERIOD 

it  seem  but  the  more  wonderful.  Yet  the  method  of 
Eratosthenes,  like  many  another  enigma,  seems  simple 
enough  once  it  is  explained.  It  required  but  the  appli- 
cation of  a  very  elementary  knowledge  of  the  geometry 
of  circles,  combined  with  the  use  of  a  fact  or  two  from 
local  geography — which  detracts  nothing  from  the 
genius  of  the  man  who  could  reason  from  such  simple 
premises  to  so  wonderful  a  conclusion. 

Stated  in  a  few  words,  the  experiment  of  Eratos- 
thenes was  this.  His  geographical  studies  had  taught 
him  that  the  town  of  Syene  lay  directly  south  of  Alex- 
andria, or,  as  we  should  say,  on  the  same  meridian  of 
latitude.  He  had  learned,  further,  that  Syene  lay 
directly  under  the  tropic,  since  it  was  reported  that 
at  noon  on  the  day  of  the  summer  solstice  the  gnomon 
there  cast  no  shadow,  while  a  deep  well  was  illumined 
to  the  bottom  by  the  sun.  A  third  item  of  knowledge, 
supplied  by  the  surveyors  of  Ptolemy,  made  the  dis- 
tance between  Syene  and  Alexandria  five  thousand 
stadia.  These,  then,  were  the  preliminary  data  re- 
quired by  Eratosthenes.  Their  significance  consists  in 
the  fact  that  here  is  a  measured  bit  of  the  earth's  arc 
five  thousand  stadia  in  length.  If  we  could  find  out 
what  angle  that  bit  of  arc  subtends,  a  mere  matter  of 
multiplication  would  give  us  the  size  of  the  earth.  But 
how  determine  this  all-important  number?  The  an- 
swer came  through  reflection  on  the  relations  of  con- 
centric circles.  If  you  draw  any  number  of  circles,  of 
whatever  size,  about  a  given  centre,  a  pair  of  radii 
drawn  from  that  centre  will  cut  arcs  of  the  same 
relative  size  from  all  the  circles.  One  circle  may  be  so 
small  that  the  actual  arc  subtended  by  the  radii  in 

229 


A   HISTORY   OF   SCIENCE 

a  given  case  may  be  but  an  inch  in  length,  while  an- 
other circle  is  so  large  that  its  corresponding  arc  is 
measured  in  millions  of  miles;  but  in  each  case  the 
same  number  of  so-called  degrees  will  represent  the  re- 
lation of  each  arc  to  its  circumference.  Now,  Eratos- 
thenes knew,  as  just  stated,  that  the  sun,  when  on  the 
meridian  on  the  day  of  the  summer  solstice,  was 
directly  over  the  town  of  Syene.  This  meant  that  at 
that  moment  a  radius  of  the  earth  projected  from 
Syene  would  point  directly  towards  the  sun.  Mean- 
while, of  course,  the  zenith  would  represent  the  pro- 
jection of  the  radius  of  the  earth  passing  through 
Alexandria.  All  that  was  required,  then,  was  to 
measure,  at  Alexandria,  the  angular  distance  of  the 
sun  from  the  zenith  at  noon  on  the  day  of  the  solstice  to 
secure  an  approximate  measurement  of  the  arc  of  the 
sun's  circumference,  corresponding  to  the  arc  of  the 
earth's  surface  represented  by  the  measured  distance 
between  Alexandria  and  Syene. 

The  reader  will  observe  that  the  measurement  could 
not  be  absolutely  accurate,  because  it  is  made  from  the 
surface  of  the  earth,  and  not  from  the  earth's  centre, 
but  the  size  of  the  earth  is  so  insignificant  in  com- 
parison with  the  distance  of  the  sun  that  this  slight 
discrepancy  could  be  disregarded. 

The  way  in  which  Eratosthenes  measured  this 
angle  was  very  simple.  He  merely  measured  the 
angle  of  the  shadow  which  his  perpendicular  gnomon 
at  Alexandria  cast  at  mid-day  on  the  day  of  the 
solstice,  when,  as  already  noted,  the  sun  was  directly 
perpendicular  at  Syene.  Now  a  glance  at  the  dia- 
gram will  make  it  clear  that  the  measurement  of 

230 


E   EARTH'S  CENTRE 


DIAGRAM     TO     ILLUSTRATE     ERATOSTHENES 

GLOBE 


MEASUREMENT     OF     THE 


Fig.  i.  AF  is  a  gnomon  at  Alexandria;  SB  a  gnomon  at  Syene;  IS  and  JK  repre- 
sent the  sun's  rays.  The  angle  actually  measured  by  Eratosthenes  is  KFA,  as  de- 
termined by  the  shadow  cast  by  the  gnomon  AF.  This  angle  is  equal  to  the  oppo- 
site angle  JFL,  which  measures  the  sun's  distance  from  the  zenith;  and  which  is  also 
equal  to  the  angle  AES — to  determine  the  size  of  which  is  the  real  object  of  the  en- 
tire measurement. 

Fig.  2  shows  the  form  of  the  gnomon  actually  employed  in  antiquity.  The 
hemisphere  KA  being  marked  with  a  scale,  it  is  obvious  that  in  actual  practice 
Eratosthenes  required  only  to  set  his  gnomon  in  the  sunlight  at  the  proper  mo- 
ment, and  read  off  the  answer  to  his  problem  at  a  glance.  The  simplicity  of  the 
method  makes  the  result  seem  all  the  more  wonderful. 


ALEXANDRIAN  OR  HELLENISTIC  PERIOD 

this  angle  of  the  shadow  is  merely  a  convenient 
means  of  determining  the  precisely  equal  opposite 
angle  subtending  an  arc  of  an  imaginary  circle  passing 
through  the  sun ;  the  arc  which,  as  already  explained, 
corresponds  with  the  arc  of  the  earth's  surface  rep- 
resented by  the  distance  between  Alexandria  and 
Syene.  He  found  this  angle  to  represent  70  12',  or 
one-fiftieth  of  the  circle.  Five  thousand  stadia, 
then,  represent  one-fiftieth  of  the  earth's  circum- 
ference; the  entire  circumference  being,  therefore, 
250,000  stadia.  Unfortunately,  we  do  not  know 
which  one  of  the  various  measurements  used  in 
antiquity  is  represented  by  the  stadia  of  Eratos- 
thenes. According  to  the  researches  of  Lepsius,  how- 
ever, the  stadium  in  question  represented  180  meters, 
and  this  would  make  the  earth,  according  to  the  meas- 
urement of  Eratosthenes,  about  twenty-eight  thousand 
miles  in  circumference,  an  answer  sufficiently  exact  to 
justify  the  wonder  which  the  experiment  excited  in  an- 
tiquity, and  the  admiration  with  which  it  has  ever 
since  been  regarded. 

Of  course  it  is  the  method,  and  not  its  details  or 
its  exact  results,  that  excites  our  interest.  And  be- 
yond question  the  method  was  an  admirable  one.  Its 
result,  however,  could  not  have  been  absolutely  ac- 
curate, because,  while  correct  in  principle,  its  data  were 
defective.  In  point  of  fact  Syene  did  not  lie  precisely 
on  the  same  meridian  as  Alexandria,  neither  did  it  lie 
exactly  on  the  tropic.  Here,  then,  are  two  elements  of 
inaccuracy.  Moreover,  it  is  doubtful  whether  Eratos- 
thenes made  allowance,  as  he  should  have  done,  for 
the  semi-diameter  of  the  sun  in  measuring  the  angle 

231 


A   HISTORY   OF    SCIENCE 

of  the  shadow.  But  these  are  mere  details,  scarcely 
worthy  of  mention  from  our  present  stand-point.  What 
perhaps  is  deserving  of  more  attention  is  the  fact  that 
this  epoch-making  measurement  of  Eratosthenes  may 
not  have  been  the  first  one  to  be  made.  A  passage  of 
Aristotle  records  that  the  size  of  the  earth  was  said  to 
be  400,000  stadia.  Some  commentators  have  thought 
that  Aristotle  merely  referred  to  the  area  of  the  in- 
habited portion  of  the  earth  and  not  to  the  circum- 
ference of  the  earth  itself,  but  his  words  seem  doubt- 
fully susceptible  of  this  interpretation ;  and  if  he  meant, 
as  his  words  seem  to  imply,  that  philosophers  of  his 
day  had  a  tolerably  precise  idea  of  the  globe,  we  must 
assume  that  this  idea  was  based  upon  some  sort  of 
measurement.  The  recorded  size,  400,000  stadia,  is  a 
sufficient  approximation  to  the  truth  to  suggest  some- 
thing more  than  a  mere  unsupported  guess.  Now, 
since  Aristotle  died  more  than  fifty  years  before  Era- 
tosthenes was  born,  his  report  as  to  the  alleged  size  of 
the  earth  certainly  has  a  suggestiveness  that  cannot 
be  overlooked;  but  it  arouses  speculations  without 
giving  an  inkling  as  to  their  solution.  If  Eratosthenes 
had  a  precursor  as  an  earth-measurer,  no  hint  or  rumor 
has  come  down  to  us  that  would  enable  us  to  guess 
who  that  precursor  may  have  been.  His  personality 
is  as  deeply  enveloped  in  the  mists  of  the  past  as  are 
the  personalities  of  the  great  prehistoric  discoverers. 
For  the  purpose  of  the  historian,  Eratosthenes  must 
stand  as  the  inventor  of  the  method  with  which  his 
name  is  associated,  and  as  the  first  man  of  whom 
we  can  say  with  certainty  that  he  measured  the 
size    of  the   earth.      Right  worthily,   then,  had   the 

232 


ALEXANDRIAN  OR  HELLENISTIC  PERIOD 

Alexandrian  philosopher  won  his  proud  title  of  "sur- 
veyor of  the  world." 

HIPPARCHUS,    "THE    LOVER    OP   TRUTH" 

Eratosthenes  outlived  most  of  his  great  contem- 
poraries. He  saw  the  turning  of  that  first  and  greatest 
century  of  Alexandrian  science,  the  third  century  be- 
fore our  era.  He  died  in  the  year  196  B.C.,  having,  it  is 
said,  starved  himself  to  death  to  escape  the  miseries 
of  blindness; — to  the  measurer  of  shadows,  life  with- 
out light  seemed  not  worth  the  living.  Eratosthenes 
left  no  immediate  successor.  A  generation  later,  how- 
ever, another  great  figure  appeared  in  the  astronom- 
ical world  in  the  person  of  Hipparchus,  a  man  who,  as 
a  technical  observer,  had  perhaps  no  peer  in  the  ancient 
world :  one  who  set  so  high  a  value  upon  accuracy  of 
observation  as  to  earn  the  title  of  "the  lover  of  truth." 
Hipparchus  was  born  at  Nicaea,  in  Bithynia,  in  the  year 
160  b.c.  His  life,  all  too  short  for  the  interests  of 
science,  ended  in  the  year  125  b.c.  The  observations 
of  the  great  astronomer  were  made  chiefly,  perhaps 
entirely,  at  Rhodes.  A  misinterpretation  of  Ptolemy's 
writings  led  to  the  idea  that  Hipparchus  performed  his 
chief  labors  in  Alexandria,  but  it  is  now  admitted  that 
there  is  no  evidence  for  this.  Delambre  doubted,  and 
most  subsequent  writers  follow  him  here,  whether  Hip- 
parchus ever  so  much  as  visited  Alexandria.  In  any 
event  there  seems  to  be  no  question  that  Rhodes  may 
claim  the  honor  of  being  the  chief  site  of  his  activities. 

It  was  Hipparchus  whose  somewhat  equivocal  com- 
ment qn  the  work  of  Eratosthenes  we  have  already 
noted.     No  counter-charge  in  kind  could  be  made 

233 


A   HISTORY    OF    SCIENCE 

against  the  critic  himself;  he  was  an  astronomer  pure 
and  simple.  His  gift  was  the  gift  of  accurate  obser- 
vation rather  than  the  gift  of  imagination.  No  scien- 
tific progress  is  possible  without  scientific  guessing, 
but  Hipparchus  belonged  to  that  class  of  observers 
with  whom  hypothesis  is  held  rigidly  subservient  to 
fact.  It  was  not  to  be  expected  that  his  mind  would 
be  attracted  by  the  heliocentric  theory  of  Aristarchus. 
He  used  the  facts  and  observations  gathered  by  his 
great  predecessor  of  Samos,  but  he  declined  to  accept 
his  theories.  For  him  the  world  was  central ;  his  prob- 
lem was  to  explain,  if  he  could,  the  irregularities  of 
motion  which  sun,  moon,  and  planets  showed  in  their 
seeming  circuits  about  the  earth.  Hipparchus  had 
the  gnomon  of  Eratosthenes — doubtless  in  a  perfected 
form — to  aid  him,  and  he  soon  proved  himself  a  master 
in  its  use.  For  him,  as  we  have  said,  accuracy  was 
everything ;  this  was  the  one  element  that  led  to  all  his 
great  successes. 

Perhaps  his  greatest  feat  was  to  demonstrate  the 
eccentricity  of  the  sun's  seeming  orbit.  We  of  to-day, 
thanks  to  Keppler  and  his  followers,  know  that  the 
earth  and  the  other  planetary  bodies  in  their  circuit 
about  the  sun  describe  an  ellipse  and  not  a  circle.  But 
in  the  day  of  Hipparchus,  though  the  ellipse  was  recog- 
nized as  a  geometrical  figure  (it  had  been  described  and 
named  along  with  the  parabola  and  hyperbola  by 
Apollonius  of  Perga,  the  pupil  of  Euclid),  yet  it  would 
have  been  the  rankest  heresy  to  suggest  an  elliptical 
course  for  any  heavenly  body.  A  metaphysical  theory, 
as  propounded  perhaps  by  the  Pythagoreans  but  ar- 
dently supported  by  Aristotle,  declared  that  the  circle 

234 


ALEXANDRIAN   OR   HELLENISTIC  PERIOD 

is  the  perfect  figure,  and  pronounced  it  inconceivable 
that  the  motions  of  the  spheres  should  be  other  than 
circular.  This  thought  dominated  the  mind  of  Hip- 
parchus,  and  so  when  his  careful  measurements  led  him 
to  the  discovery  that  the  northward  and  southward 
journeyings  of  the  sun  did  not  divide  the  year  into  four 
equal  parts,  there  was  nothing  open  to  him  but  to  either 
assume  that  the  earth  does  not  lie  precisely  at  the  cen- 
tre of  the  sun's  circular  orbit  or  to  find  some  alternative 
hypothesis. 

In  point  of  fact,  the  sun  (reversing  the  point  of  view 
in  accordance  with  modern  discoveries)  does  lie  at  one 
focus  of  the  earth's  elliptical  orbit,  and  therefore  away 
from  the  physical  centre  of  that  orbit ;  in  other  words, 
the  observations  of  Hipparchus  were  absolutely  ac- 
curate. He  was  quite  correct  in  finding  that  the  sun 
spends  more  time  on  one  side  of  the  equator  than  on  the 
other.  When,  therefore,  he  estimated  the  relative  dis- 
tance of  the  earth  from  the  geometrical  centre  of  the 
sun's  supposed  circular  orbit,  and  spoke  of  this  as  the 
measure  of  the  sun's  eccentricity,  he  propounded  a 
theory  in  which  true  data  of  observation  were  curious- 
ly mingled  with  a  positively  inverted  theory.  That  the 
theory  of  Hipparchus  was  absolutely  consistent  with 
all  the  facts  of  this  particular  observation  is  the  best 
evidence  that  could  be  given  of  the  difficulties  that 
stood  in  the  way  of  a  true  explanation  of  the  mechan- 
ism of  the  heavens. 

But  it  is  not  merely  the  sun  which  was  observed  to 
vary  in  the  speed  of  its  orbital  progress ;  the  moon  and 
the  planets  also  show  curious  accelerations  and  re- 
tardations of  motion.     The  moon  in  particular  re- 

235 


A   HISTORY   OF   SCIENCE 

ceived  most  careful  attention  from  Hipparchus.  Dom- 
inated by  his  conception  of  the  perfect  spheres,  he 
could  find  but  one  explanation  of  the  anomalous  mo- 
tions which  he  observed,  and  this  was  to  assume  that 
the  various  heavenly  bodies  do  not  fly  on  in  an  un- 
varying arc  in  their  circuit  about  the  earth,  but  de- 
scribe minor  circles  as  they  go  which  can  be  likened 
to  nothing  so  tangibly  as  to  a  light  attached  to  the 
rim  of  a  wagon-wheel  in  motion.  If  such  an  invisible 
wheel  be  imagined  as  carrying  the  sun,  for  example, 
on  its  rim,  while  its  invisible  hub  follows  unswervingly 
the  circle  of  the  sun's  mean  orbit  (this  wheel,  be  it 
understood,  lying  in  the  plane  of  the  orbit,  not  at  right- 
angles  to  it),  then  it  must  be  obvious  that  while  the  hub 
remains  always  at  the  same  distance  from  the  earth, 
the  circling  rim  will  carry  the  sun  nearer  the  earth, 
then  farther  away,  and  that  while  it  is  traversing  that 
portion  of  the  arc  which  brings  it  towards  the  earth, 
the  actual  forward  progress  of  the  sun  will  be  retarded 
notwithstanding  the  uniform  motion  of  the  hub,  just 
as  it  will  be  accelerated  in  the  opposite  arc.  Now,  if 
we  suppose  our  sun-bearing  wheel  to  turn  so  slowly 
that  the  sun  revolves  but  once  about  its  imaginary 
hub  while  the  wheel  itself  is  making  the  entire  circuit 
of  the  orbit,  we  shall  have  accounted  for  the  observed 
fact  that  the  sun  passes  more  quickly  through  one-half 
of  the  orbit  than  through  the  other.  Moreover,  if  we 
can  visualize  the  process  and  imagine  the  sun  to  have 
left  a  visible  line  of  fire  behind  him  throughout  the 
course,  we  shall  see  that  in  reality  the  two  circular 
motions  involved  have  really  resulted  in  producing  an 
elliptical  orbit. 

236 


ALEXANDRIAN  OR  HELLENISTIC  PERIOD 

The  idea  is  perhaps  made  clearer  if  we  picture  the 
actual  progress  of  the  lantern  attached  to  the  rim  of  an 
ordinary  cart-wheel.  When  the  cart  is  drawn  forward 
the  lantern  is  made  to  revolve  in  a  circle  as  regards  the 
hub  of  the  wheel,  but  since  that  hub  is  constantly  going 
forward,  the  actual  path  described  by  the  lantern  is 
not  a  circle  at  all  but  a  waving  line.  It  is  precisely  the 
same  with  the  imagined  course  of  the  sun  in  its  orbit, 
only  that  we  view  these  lines  just  as  we  should  view 
the  lantern  on  the  wheel  if  we  looked  at  it  from  di- 
rectly above  and  not  from  the  side.  The  proof  that 
the  sun  is  describing  this  waving  line,  and  therefore 
must  be  considered  as  attached  to  an  imaginary  wheel, 
is  furnished,  as  it  seemed  to  Hipparchus,  by  the  ob- 
served fact  of  the  sun's  varying  speed. 

That  is  one  way  of  looking  at  the  matter.  It  is  an 
hypothesis  that  explains  the  observed  facts — after  a 
fashion,  and  indeed  a  very  remarkable  fashion.  The 
idea  of  such  an  explanation  did  not  originate  with  Hip- 
parchus. The  germs  of  the  thought  were  as  old  as  the 
Pythagorean  doctrine  that  the  earth  revolves  about  a 
centre  that  we  cannot  see.  Eudoxus  gave  the  concep- 
tion greater  tangibility,  and  may  be  considered  as  the 
father  of  this  doctrine  of  wheels — epicycles,  as  they 
came  to  be  called.  Two  centuries  before  the  time  of 
Hipparchus  he  conceived  a  doctrine  of  spheres  which 
Aristotle  found  most  interesting,  and  which  served  to 
explain,  along  the  lines  we  have  just  followed,  the  ob- 
served motions  of  the  heavenly  bodies.  Calippus,  the 
reformer  of  the  calendar,  is  said  to  have  carried  an  ac- 
count of  this  theory  to  Aristotle.  As  new  irregularities 
of  motion  of  the  sun,  moon,  and  planetary  bodies  were 

237 


A   HISTORY    OF   SCIENCE 

pointed  out,  new  epicycles  were  invented.  There  is 
no  limit  to  the  number  of  imaginary  circles  that  may  be 
inscribed  about  an  imaginary  centre,  and  if  we  con- 
ceive each  one  of  these  circles  to  have  a  proper  motion 
of  its  own,  and  each  one  to  carry  the  sun  in  the  line  of 
that  motion,  except  as  it  is  diverted  by  the  other  mo- 
tions— if  we  can  visualize  this  complex  mingling  of 
wheels — we  shall  certainly  be  able  to  imagine  the  heav- 
enly body  which  lies  at  the  juncture  of  all  the  rims, 
as  being  carried  forward  in  as  erratic  and  wobbly  a 
manner  as  could  be  desired.  In  other  words,  the  theory 
of  epicycles  will  account  for  all  the  facts  of  the  ob- 
served motions  of  all  the  heavenly  bodies,  but  in  so 
doing  it  fills  the  universe  with  a  most  bewildering  net- 
work of  intersecting  circles.  Even  in  the  time  of  Ca- 
lippus  fifty-five  of  these  spheres  were  computed. 

We  may  well  believe  that  the  clear-seeing  Aristar- 
chus  would  look  askance  at  such  a  complex  system  of 
imaginary  machinery.  But  Hipparchus,  pre-eminent- 
ly an  observer  rather  than  a  theorizer,  seems  to  have 
been  content  to  accept  the  theory  of  epicycles  as  he 
found  it,  though  his  studies  added  to  its  complexities; 
and  Hipparchus  was  the  dominant  scientific  personality 
of  his  century.  What  he  believed  became  as  a  law 
to  his  immediate  successors.  His  tenets  were  accepted 
as  final  by  their  great  popularizer,  Ptolemy,  three  cen- 
turies later;  and  so  the  heliocentric  theory  of  Aristar- 
chus  passed  under  a  cloud  almost  at  the  hour  of  its 
dawning,  there  to  remain  obscured  and  forgotten  for 
the  long  lapse  of  centuries.  A  thousand  pities  that  the 
greatest  observing  astronomer  of  antiquity  could  not, 
like  one  of  his  great  precursors,  have  approached  as- 

238 


ALEXANDRIAN  OR  HELLENISTIC  PERIOD 

tronomy  from  the  stand-point  of  geography  and  poetry, 
Had  he  done  so,  perhaps  he  might  have  reflected,  like 
Aristarchus  before  him,  that  it  seems  absurd  for  our 
earth  to  hold  the  giant  sun  in  thraldom ;  then  perhaps 
his  imagination  would  have  reached  out  to  the  helio- 
centric doctrine,  and  the  cobweb  hypothesis  of  epi- 
cycles, with  that  yet  more  intangible  figment  of  the 
perfect  circle,  might  have  been  wiped  away. 

But  it  was  not  to  be.  With  Aristarchus  the  scien- 
tific imagination  had  reached  its  highest  flight;  but 
with  Hipparchus  it  was  beginning  to  settle  back  into 
regions  of  foggier  atmosphere  and  narrower  horizons. 
For  what,  after  all,  does  it  matter  that  Hipparchus 
should  go  on  to  measure  the  precise  length  of  the  year 
and  the  apparent  size  of  the  moon's  disk ;  that  he  should 
make  a  chart  of  the  heavens  showing  the  place  of  1080 
stars;  even  that  he  should  discover  the  precession 
of  the  equinox; — what,  after  all,  is  the  significance  of 
these  details  as  against  the  all-essential  fact  that  the 
greatest  scientific  authority  of  his  century — the  one 
truly  heroic  scientific  figure  of  his  epoch — should  have 
lent  all  the  forces  of  his  commanding  influence  to  the 
old,  false  theory  of  cosmology,  when  the  true  theory 
had  been  propounded  and  when  he,  perhaps,  was  the 
only  man  in  the  world  who  might  have  substantiated 
and  vitalized  that  theory  ?  It  is  easy  to  overestimate 
the  influence  of  any  single  man,  and,  contrariwise,  to 
underestimate  the  power  of  the  Zeitgeist.  But  when 
we  reflect  that  the  doctrines  of  Hipparchus,  as  pro- 
mulgated by  Ptolemy,  became,  as  it  were,  the  last 
word  of  astronomical  science  for  both  the  Eastern  and 
Western  worlds,  and  so  continued  after  a  thousand 

239 


A   HISTORY   OF   SCIENCE 

years,  it  is  perhaps  not  too  much  to  say  that  Hippar- 
chus,  "  the  lover  of  truth,"  missed  one  of  the  greatest 
opportunities  for  the  promulgation  of  truth  ever  vouch- 
safed to  a  devotee  of  pure  science. 

But  all  this,  of  course,  detracts  nothing  from  the 
merits  of  Hipparchus  as  an  observing  astronomer. 
A  few  words  more  must  be  said  as  to  his  specific  dis- 
coveries in  this  field.  According  to  his  measurement, 
the  tropic  year  consists  of  365  days,  5  hours,  and  49 
minutes,  varying  thus  only  12  seconds  from  the  true 
year,  as  the  modern  astronomer  estimates  it.  Yet 
more  remarkable,  because  of  the  greater  difficulties 
involved,  was  Hipparchus's  attempt  to  measure  the 
actual  distance  of  the  moon.  Aristarchus  had  made 
a  similar  attempt  before  him.  Hipparchus  based  his 
computations  on  studies  of  the  moon  in  eclipse,  and  he 
reached  the  conclusion  that  the  distance  of  the  moon  is 
equal  to  59  radii  of  the  earth  (in  reality  it  is  60.27 
radii).  Here,  then,  was  the  measure  of  the  base-line 
of  that  famous  triangle  with  which  Aristarchus  had 
measured  the  distance  of  the  sun.  Hipparchus  must 
have  known  of  that  measurement,  since  he  quotes  the 
work  of  Aristarchus  in  other  fields.  Had  he  now  but 
repeated  the  experiment  of  Aristarchus,  with  his  per- 
fected instruments  and  his  perhaps  greater  observa- 
tional skill,  he  was  in  position  to  compute  the  actual 
distance  of  the  sun  in  terms  not  merely  of  the  moon's 
distance  but  of  the  earth's  radius.  And  now  there 
was  the  experiment  of  Eratosthenes  to  give  the  length 
of  that  radius  in  precise  terms.  In  other  words,  Hip- 
parchus might  have  measured  the  distance  of  the  sun 
in  stadia.     But  if  he  had  made  the  attempt — and,  in- 

240 


ALEXANDRIAN  OR  HELLENISTIC  PERIOD 

deed,  it  is  more  than  likely  that  he  did  so — the  elements 
of  error  in  his  measurements  would  still  have  kept 
him  wide  of  the  true  figures. 

The  chief  studies  of  Hipparchus  were  directed,  as 
we  have  seen,  towards  the  sun  and  the  moon,  but  a 
phenomenon  that  occurred  in  the  year  134  B.C.  led 
him  for  a  time  to  give  more  particular  attention  to  the 
fixed  stars.  The  phenomenon  in  question  was  the 
sudden  outburst  of  a  new  star;  a  phenomenon  which 
has  been  repeated  now  and  again,  but  which  is  suffi- 
ciently rare  and  sufficiently  mysterious  to  have  ex- 
cited the  unusual  attention  of  astronomers  in  all  gen- 
erations. Modern  science  offers  an  explanation  of  the 
phenomenon,  as  we  shall  see  in  due  course.  We  do 
not  know  that  Hipparchus  attempted  to  explain  it, 
but  he  was  led  to  make  a  chart  of  the  heavens,  probably 
with  the  idea  of  guiding  future  observers  in  the  ob- 
servation of  new  stars.  Here  again  Hipparchus  was 
not  altogether  an  innovator,  since  a  chart  showing  the 
brightest  stars  had  been  made  by  Eratosthenes;  but 
the  new  charts  were  much  elaborated. 

The  studies  of  Hipparchus  led  him  to  observe  the 
stars  chiefly  with  reference  to  the  meridian  rather  than 
with  reference  to  their  rising,  as  had  hitherto  been  the 
custom.  In  making  these  studies  of  the  relative  po- 
sition of  the  stars,  Hipparchus  was  led  to  compare  his 
observations  with  those  of  the  Babylonians,  which,  it 
was  said,  Alexander  had  caused  to  be  transmitted  to 
Greece.  He  made  use  also  of  the  observations  of 
Aristarchus  and  others  of  his  Greek  precursors.  The 
result  of  his  comparisons  proved  that  the  sphere  of 
the  fixed  stars  had  apparently  shifted  its  position  in 

VOL.  I.— 16  241 


A   HISTORY    OF   SCIENCE 

reference  to  the  plane  of  the  sun's  orbit — that  is  to  say, 
the  plane  of  the  ecliptic  no  longer  seemed  to  cut  the 
sphere  of  the  fixed  stars  at  precisely  the  point  where 
the  two  coincided  in  former  centuries.  The  plane  of 
the  ecliptic  must  therefore  be  conceived  as  slowly  re- 
volving in  such  a  way  as  gradually  to  circumnavigate 
the  heavens.  This  important  phenomenon  is  described 
as  the  precession  of  the  equinoxes. 

It  is  much  in  question  whether  this  phenomenon  was 
not  known  to  the  ancient  Egyptian  astronomers ;  but 
in  any  event,  Hipparchus  is  to  be  credited  with  dem- 
onstrating the  fact  and  making  it  known  to  the  West- 
ern world.  A  further  service  was  rendered  theoretical 
astronomy  by  Hipparchus  through  his  invention  of  the 
planosphere,  an  instrument  for  the  representation  of 
the  mechanism  of  the  heavens.  His  computations  of 
the  properties  of  the  spheres  led  him  also  to  what  was 
virtually  a  discovery  of  the  method  of  trigonometry, 
giving  him,  therefore,  a  high  position  in  the  field  of 
mathematics.  All  in  all,  then,  Hipparchus  is  a  most 
heroic  figure.  He  may  well  be  considered  the  greatest 
star-gazer  of  antiquity,  though  he  cannot,  without  in- 
justice to  his  great  precursors,  be  allowed  the  title 
which  is  sometimes  given  him  of  "  father  of  systematic 
astronomy." 

CTESIBTUS    AND    HERO  I    MAGICIANS    OF   ALEXANDRIA 

Just  about  the  time  when  Hipparchus  was  working 
out  at  Rhodes  his  puzzles  of  celestial  mechanics,  there 
was  a  man  in  Alexandria  who  was  exercising  a  strangely 
inventive  genius  over  mechanical  problems  of  another 
sort;  a  man  who,  following  the  example  set  by  Archi- 

242 


ALEXANDRIAN  OR  HELLENISTIC  PERIOD 

medes  a  century  before,  was  studying  the  problems  of 
matter  and  putting  his  studies  to  practical  application 
through  the  invention  of  weird  devices.  The  man's 
name  was  Ctesibius.  We  know  scarcely  more  of  him 
than  that  he  lived  in  Alexandria,  probably  in  the  first 
half  of  the  second  century  B.C.  His  antecedents,  the 
place  and  exact  time  of  his  birth  and  death,  are  quite 
unknown.  Neither  are  we  quite  certain  as  to  the  pre- 
cise range  of  his  studies  or  the  exact  number  of  his  dis- 
coveries. It  appears  that  he  had  a  pupil  named  Hero, 
whose  personality,  unfortunately,  is  scarcely  less  ob- 
scure than  that  of  his  master,  but  who  wrote  a  book 
through  which  the  record  of  the  master's  inventions 
was  preserved  to  posterity.  Hero,  indeed,  wrote  sev- 
eral books,  though  only  one  of  them  has  been  preserved. 
The  ones  that  are  lost  bear  the  following  suggestive 
titles:  On  the  Construction  of  Slings;  On  the  Construc- 
tion of  Missiles;  On  the  Automaton;  On  the  Method  of 
Lifting  Heavy  Bodies;  On  the  Dioptric  or  Spying-tube. 
The  work  that  remains  is  called  Pneumatics,  and  so 
interesting  a  work  it  is  as  to  make  us  doubly  regret  the 
loss  of  its  companion  volumes.  Had  these  other  books 
been  preserved  we  should  doubtless  have  a  clearer  in- 
sight than  is  now  possible  into  some  at  least  of  the 
mechanical  problems  that  exercised  the  minds  of  the 
ancient  philosophers.  The  book  that  remains  is  chiefly 
concerned,  as  its  name  implies,  with  the  study  of  gases, 
or,  rather,  with  the  study  of  a  single  gas,  this  being, 
of  course,  the  air.  But  it  tells  us  also  of  certain  studies 
in  the  dynamics  of  water  that  are  most  interesting, 
and  for  the  historian  of  science  most  important. 
Unfortunately,  the  pupil  of  Ctesibius,  whatever  his 

243 


A   HISTORY   OF   SCIENCE 

ingenuity,  was  a  man  with  a  deficient  sense  of  the  ethics 
of  science.  He  tells  us  in  his  preface  that  the  object 
of  his  book  is  to  record  some  ingenious  discoveries  of 
others,  together  with  additional  discoveries  of  his  own, 
but  nowhere  in  the  book  itself  does  he  give  us  the 
slightest  clew  as  to  where  the  line  is  drawn  between  the 
old  and  the  new.  Once,  in  discussing  the  weight  of 
water,  he  mentions  the  law  of  Archimedes  regarding  a 
floating  body,  but  this  is  the  only  case  in  which  a  scien- 
tific principle  is  traced  to  its  source  or  in  which  credit 
is  given  to  any  one  for  a  discovery.  This  is  the  more 
to  be  regretted  because  Hero  has  discussed  at  some 
length  the  theories  involved  in  the  treatment  of  his 
subject.  This  reticence  on  the  part  of  Hero,  combined 
with  the  fact  that  such  somewhat  later  writers  as 
Pliny  and  Vitruvius  do  not  mention  Hero's  name, 
while  they  frequently  mention  the  name  of  his  master, 
Ctesibius,  has  led  modern  critics  to  a  somewhat  scep- 
tical attitude  regarding  the  position  of  Hero  as  an  actual 
discoverer. 

The  man  who  would  coolly  appropriate  some  dis- 
coveries of  others  under  cloak  of  a  mere  prefatorial  ref- 
erence was  perhaps  an  expounder  rather  than  an  in- 
novator, and  had,  it  is  shrewdly  suspected,  not  much  of 
his  own  to  offer.  Meanwhile,  it  is  tolerably  certain  that 
Ctesibius  was  the  discoverer  of  the  principle  of  the  si- 
phon, of  the  forcing-pump,  and  of  a  pneumatic  organ. 
An  examination  of  Hero's  book  will  show  that  these  are 
really  the  chief  principles  involved  in  most  of  the  vari- 
ous interesting  mechanisms  which  he  describes.  We 
are  constrained,  then,  to  believe  that  the  inventive 
genius  who  was  really  responsible  for  the  mechanisms 

244 


ALEXANDRIAN  OR  HELLENISTIC  PERIOD 

we  are  about  to  describe  was  Ctesibius,  the  master. 
Yet  we  owe  a  debt  of  gratitude  to  Hero,  the  pupil,  for 
having  given  wider  vogue  to  these  discoveries,  and  in 
particular  for  the  discussion  of  the  principles  of  hy- 
drostatics and  pneumatics  contained  in  the  introduc- 
tion to  his  book.  This  discussion  furnishes  us  almost 
our  only  knowledge  as  to  the  progress  of  Greek  philoso- 
phers in  the  field  of  mechanics  since  the  time  of  Archi- 
medes. 

The  main  purpose  of  Hero  in  his  preliminary  thesis 
has  to  do  with  the  nature  of  matter,  and  recalls,  there- 
fore, the  studies  of  Anaxagoras  and  Democritus. 
Hero,  however,  approaches  his  subject  from  a  purely 
material  or  practical  stand-point.  He  is  an  explicit 
champion  of  what  we  nowadays  call  the  molecular 
theory  of  matter.  "  Every  body,"  he  tells  us,  "  is  com- 
posed of  minute  particles,  between  which  are  empty 
spaces  less  than  these  particles  of  the  body.  It  is, 
therefore,  erroneous  to  say  that  there  is  no  vacuum 
except  by  the  application  of  force,  and  that  every  space 
is  full  either  of  air  or  water  or  some  other  substance. 
But  in  proportion  as  any  one  of  these  particles  recedes, 
some  other  follows  it  and  fills  the  vacant  space ;  there- 
fore there  is  no  continuous  vacuum,  except  by  the 
application  of  some  force  [like  suction] — that  is  to 
say,  an  absolute  vacuum  is  never  found,  except  as  it  is 
produced  artificially."  Hero  brings  forward  some  thor- 
oughly convincing  proofs  of  the  thesis  he  is  maintaining. 
"  If  there  were  no  void  places  between  the  particles  of 
water,"  he  says,  "  the  rays  of  light  could  not  penetrate 
the  water;  moreover,  another  liquid,  such  as  wine, 
could  not  spread  itself  through  the  water,  as  it  is  ob- 

245 


A   HISTORY   OF   SCIENCE 

served  to  do,  were  the  particles  of  water  absolutely 
continuous."  The  latter  illustration  is  one  the  validity 
of  which  appeals  as  forcibly  to  the  physicists  of  to-day 
as  it  did  to  Hero.  The  same  is  true  of  the  argument 
drawn  from  the  compressibility  of  gases.  Hero  has 
evidently  made  a  careful  study  of  this  subject  He 
knows  that  an  inverted  tube  full  of  air  may  be  im- 
mersed in  water  without  becoming  wet  on  the  inside, 
proving  that  air  is  a  physical  substance ;  but  he  knows 
also  that  this  same  air  may  be  caused  to  expand  to  a 
much  greater  bulk  by  the  application  of  heat,  or  may, 
on  the  other  hand,  be  condensed  by  pressure,  in  which 
case,  as  he  is  well  aware,  the  air  exerts  force  in  the  at- 
tempt to  regain  its  normal  bulk.  But,  he  argues, 
surely  we  are  not  to  believe  that  the  particles  of  air 
expand  to  fill  all  the  space  when  the  bulk  of  air  as  a 
whole  expands  under  the  influence  of  heat ;  nor  can  we 
conceive  that  the  particles  of  normal  air  are  in  actual 
contact,  else  we  should  not  be  able  to  compress  the  air. 
Hence  his  conclusion,  which,  as  we  have  seen,  he  makes 
general  in  its  application  to  all  matter,  that  there  are 
spaces,  or,  as  he  calls  them,  vacua,  between  the  par- 
ticles that  go  to  make  up  all  substances,  whether 
liquid,  solid,  or  gaseous. 

Here,  clearly  enough,  was  the  idea  of  the  "atomic" 
nature  of  matter  accepted  as  a  fundamental  notion. 
The  argumentative  attitude  assumed  by  Hero  shows 
that  the  doctrine  could  not  be  expected  to  go  un- 
challenged. But,  on  the  other  hand,  there  is  nothing 
in  his  phrasing  to  suggest  an  intention  to  claim  orig- 
inality for  any  phase  of  the  doctrine.  We  may  infer 
that  in  the  three  hundred  years  that  had  elapsed  since 

246 


DEVICE   FOR   CAUSING   THE   DOORS    OF   THE   TEMPLE   TO   OPEN 
WHEN    THE    FIRE    ON    THE    ALTAR    IS    LIGHTED 

(Air  heated  in  the  altar  F  drives  water  from  the  closed  receptacle  H  through  the 
tube  KL  into  the  bucket  M,  which  descends  through  gravity,  thus  opening  the 
doors.  When  the  altar  cools,  the  air  contracts,  the  water  is  sucked  from  the 
bucket,  and  the  weight  and  pulley  close  the  doors.     See  p.  248.) 


ALEXANDRIAN  OR  HELLENISTIC  PERIOD 

the  time  of  Anaxagoras,  that  philosopher's  idea  of  the 
molecular  nature  of  matter  had  gained  fairly  wide 
currency.  As  to  the  expansive  power  of  gas,  which 
Hero  describes  at  some  length  without  giving  us  a  clew 
to  his  authorities,  we  may  assume  that  Ctesibius  was 
an  original  worker,  yet  the  general  facts  involved  were 
doubtless  much  older  than  his  day.  Hero,  for  ex- 
ample, tells  us  of  the  cupping-glass  used  by  physicians, 
which  he  says  is  made  into  a  vacuum  by  burning  up 
the  air  in  it ;  but  this  apparatus  had  probably  been  long 
in  use,  and  Hero  mentions  it  not  in  order  to  describe 
the  ordinary  cupping-glass  which  is  referred  to,  but  a 
modification  of  it.  He  refers  to  the  old  form  as  if  it 
were  something  familiar  to  all. 

Again,  we  know  that  Empedocles  studied  the  press- 
ure of  the  air  in  the  fifth  century  B.C.,  and  discovered 
that  it  would  support  a  column  of  water  in  a  closed 
tube,  so  this  phase  of  the  subject  is  not  new.  But  there 
is  no  hint  anywhere  before  this  work  of  Hero  of  a  clear 
understanding  that  the  expansive  properties  of  the  air 
when  compressed,  or  when  heated,  may  be  made  avail- 
able as  a  motor  power.  Hero,  however,  has  the  clearest 
notions  on  the  subject  and  puts  them  to  the  practical 
test  of  experiment.  Thus  he  constructs  numerous 
mechanisms  in  which  the  expansive  power  of  air  un- 
der pressure  is  made  to  do  work,  and  others  in  which 
the  same  end  is  accomplished  through  the  expansive 
power  of  heated  air.  For  example,  the  doors  of  a  tem- 
ple are  made  to  swing  open  automatically  when  a  fire 
is  lighted  on  a  distant  altar,  closing  again  when  the  fire 
dies  out — effects  which  must  have  filled  the  minds  of 
the  pious  observers  with  bewilderment  and  wonder, 

247 


A   HISTORY   OF   SCIENCE 

serving  a  most  useful  purpose  for  the  priests,  who  alone, 
we  may  assume,  were  in  the  secret.  There  were  two 
methods  by  which  this  apparatus  was  worked.  In 
one  the  heated  air  pressed  on  the  water  in  a  close  re- 
tort connected  with  the  altar,  forcing  water  out  of  the 
retort  into  a  bucket,  which  by  its  weight  applied  a 
force  through  pulleys  and  ropes  that  turned  the  stand- 
ards on  which  the  temple  doors  revolved.  When  the 
fire  died  down  the  air  contracted,  the  water  was  si- 
phoned back  from  the  bucket,  which,  being  thus  light- 
ened, let  the  doors  close  again  through  the  action  of  an 
ordinary  weight.  The  other  method  was  a  slight  mod- 
ification, in  which  the  retort  of  water  was  dispensed 
with  and  a  leather  sack  like  a  large  football  substitued. 
The  ropes  and  pulleys  were  connected  with  this  sack, 
which  exerted  a  pull  when  the  hot  air  expanded,  and 
which  collapsed  and  thus  relaxed  its  strain  when  the 
air  cooled.  A  glance  at  the  illustrations  taken  from 
Hero's  book  will  make  the  details  clear. 

Other  mechanisms  utilized  a  somewhat  different 
combination  of  weights,  pulleys,  and  siphons,  operated 
by  the  expansive  power  of  air,  unheated  but  under 
pressure,  such  pressure  being  applied  with  a  force- 
pump,  or  by  the  weight  of  water  running  into  a  closed 
receptacle.  One  such  mechanism  gives  us  a  constant 
jet  of  water  or  perpetual  fountain.  Another  curious 
application  of  the  principle  furnishes  us  with  an  elab- 
orate toy,  consisting  of  a  group  of  birds  which  alter- 
nately whistle  or  are  silent,  while  an  owl  seated  on  a 
neighboring  perch  turns  towards  the  birds  when  their 
song  begins  and  away  from  them  when  it  ends.  The 
"singing"  of  the  birds,  it  must  be  explained,  is  pro- 

248 


THE    STEAM-ENGINE    OF    HERO 

(The  steam  generated  in  the  receptacle  AB  passes  through  the  tube  EF  into  the 
globe,  and  escapes  through  the  bent  tubes  H  and  K,  causing  the  globe  to 
rotate  on  the  axis  LG.     See  p.  250.) 


ALEXANDRIAN  OR  HELLENISTIC  PERIOD 

duced  by  the  expulsion  of  air  through  tiny  tubes  pass- 
ing up  through  their  throats  from  a  tank  below.  The 
owl  is  made  to  turn  by  a  mechanism  similar  to  that 
which  manipulates  the  temple  doors.  The  pressure  is 
supplied  merely  by  a  stream  of  running  water,  and  the 
periodical  silence  of  the  birds  is  due  to  the  fact  that  this 
pressure  is  relieved  through  the  automatic  siphoning 
off  of  the  water  when  it  reaches  a  certain  height.  The 
action  of  the  siphon,  it  may  be  added,  is  correctly  ex- 
plained by  Hero  as  due  to  the  greater  weight  of  the 
water  in  the  longer  arm  of  the  bent  tube.  As  before 
mentioned,  the  siphon  is  repeatedly  used  in  these 
mechanisms  of  Hero.  The  diagram  will  make  clear 
the  exact  application  of  it  in  the  present  most  ingenious 
mechanism.  We  may  add  that  the  principle  of  the 
whistle  was  a  favorite  one  of  Hero.  By  the  aid  of  a 
similar  mechanism  he  brought  about  the  blowing  of 
trumpets  when  the  temple  doors  were  opened,  a  phe- 
nomenon which  must  greatly  have  enhanced  the  mysti- 
fication. It  is  possible  that  this  principle  was  util- 
ized also  in  connection  with  statues  to  produce  seem- 
ingly supernatural  effects.  This  may  be  the  explana- 
tion of  the  tradition  of  the  speaking  statue  in  the  tem- 
ple of  Ammon  at  Thebes. 

The  utilization  of  the  properties  of  compressed  air 
was  not  confined,  however,  exclusively  to  mere  toys, 
or  to  produce  miraculous  effects.  The  same  principle 
was  applied  to  a  practical  fire-engine,  worked  by  levers 
and  force-pumps;  an  apparatus,  in  short,  altogether 
similar  to  that  still  in  use  in  rural  districts.  A  slightly 
different  application  of  the  motive  power  of  expanding 
air  is  furnished  in  a  very  curious  toy  called  "the  dan- 

249 


A   HISTORY   OF   SCIENCE 

cing  figures."  In  this,  air  heated  in  a  retort  like  a 
miniature  altar  is  allowed  to  escape  through  the  sides 
of  two  pairs  of  revolving  arms  precisely  like  those  of 
the  ordinary  revolving  fountain  with  which  we  are  ac- 
customed to  water  our  lawns,  the  revolving  arms  being 
attached  to  a  plane  on  which  several  pairs  of  statuettes 
representing  dancers  are  placed.  An  even  more  in- 
teresting application  of  this  principle  of  setting  a  wheel 
in  motion  is  furnished  in  a  mechanism  which  must  be 
considered  the  earliest  of  steam-engines.  Here,  as  the 
name  implies,  the  gas  supplying  the  motive  power  is 
actually  steam.  The  apparatus  made  to  revolve  is  a 
globe  connected  with  the  steam-retort  by  a  tube  which 
serves  as  one  of  its  axes,  the  steam  escaping  from  the 
globe  through  two  bent  tubes  placed  at  either  end  of  an 
equatorial  diameter.  It  does  not  appear  that  Hero 
had  any  thought  of  making  practical  use  of  this  steam- 
engine.  It  was  merely  a  curious  toy — nothing  more. 
Yet  had  not  the  age  that  succeeded  that  of  Hero  been 
one  in  which  inventive  genius  was  dormant,  some  one 
must  soon  have  hit  upon  the  idea  that  this  steam- 
engine  might  be  improved  and  made  to  serve  a  useful 
purpose.  As  the  case  stands,  however,  there  was  no 
advance  made  upon  the  steam  motor  of  Hero  for  al- 
most two  thousand  years.  And,  indeed,  when  the 
practical  application  of  steam  was  made,  towards  the 
close  of  the  eighteenth  century,  it  was  made  probably 
quite  without  reference  to  the  experiment  of  Hero, 
though  knowledge  of  his  toy  may  perhaps  have  given 
a  clew  to  Watt  or  his  predecessors. 

In  recent  times  there  has  been  a  tendency  to  give 
to  this  steam-engine  of  Hero  something  more  than 

2qo 


THE    SLOT-MACHINE    OF    HERO 

(The  coin  introduced  at  A  falls  on  the  lever  R,  and  by  its  weight  opens  the 
valve  S,  permitting  the  liquid  to  escape  through  the  invisible  tube  LM.  As 
the  lever  tips,  the  coin  slides  off  and  the  valve  closes.  The  liquid  in  the  tank 
must  of  course  be  kept  above  F.     See  p.  251.) 


ALEXANDRIAN  OR  HELLENISTIC  PERIOD 

full  meed  of  appreciation.  To  be  sure,  it  marked  a 
most  important  principle  in  the  conception  that  steam 
might  be  used  as  a  motive  power,  but,  except  in  the 
demonstration  of  this  principle,  the  mechanism  of 
Hero  was  much  too  primitive  to  be  of  any  importance. 
But  there  is  one  mechanism  described  by  Hero  which 
was  a  most  explicit  anticipation  of  a  device,  which  pre- 
sumably soon  went  out  of  use,  and  which  was  not  re- 
invented until  towards  the  close  of  the  nineteenth  cen- 
tury. This  was  a  device  which  has  become  familiar 
in  recent  times  as  the  penny-in-the-slot  machine. 
When  towards  the  close  of  the  nineteenth  century  some 
inventive  craftsman  hit  upon  the  idea  of  an  automatic 
machine  to  supply  candy,  a  box  of  cigarettes,  or  a  whiff 
of  perfumery,  he  may  or  may  not  have  borrowed  his 
idea  from  the  slot-machine  of  Hero ;  but  in  any  event, 
instead  of  being  an  innovator  he  was  really  two  thou- 
sand years  behind  the  times,  for  the  slot-machine  of 
Hero  is  the  precise  prototype  of  these  modern  ones. 

The  particular  function  which  the  mechanism  of 
Hero  was  destined  to  fulfil  was  the  distribution  of  a 
jet  of  water,  presumably  used  for  sacramental  pur- 
poses, which  was  given  out  automatically  when  a  five- 
drachma  coin  was  dropped  into  the  slot  at  the  top  of 
the  machine.  The  internal  mechanism  of  the  machine 
was  simple  enough,  consisting  merely  of  a  lever  oper- 
ating a  valve  which  was  opened  by  the  weight  of  the 
coin  dropping  on  the  little  shelf  at  the  end  of  the  lever, 
and  which  closed  again  when  the  coin  slid  off  the  shelf. 
The  illustration  will  show  how  simple  this  mechanism 
was.  Yet  to  the  worshippers,  who  probably  had  en- 
tered the  temple  through  doors  miraculously  opened, 

251 


A   HISTORY   OF   SCIENCE 

and  who  now  witnessed  this  seemingly  intelligent  re- 
sponse of  a  machine,  the  result  must  have  seemed 
mystifying  enough;  and,  indeed,  for  us  also,  when  we 
consider  how  relatively  crude  was  the  mechanical 
knowledge  of  the  time,  this  must  seem  nothing  less 
than  marvellous.  As  in  imagination  we  walk  up  to  the 
sacred  tank,  drop  our  drachma  in  the  slot,  and  hold 
our  hand  for  the  spurt  of  holy-water,  can  we  realize 
that  this  is  the  land  of  the  Pharaohs,  not  England  or 
America ;  that  the  kingdom  of  the  Ptolemies  is  still  at 
its  height ;  that  the  republic  of  Rome  is  mistress  of  the 
world;  that  all  Europe  north  of  the  Alps  is  inhabited 
solely  by  barbarians ;  that  Cleopatra  and  Julius  Caesar 
are  yet  unborn ;  that  the  Christian  era  has  not  yet  be- 
gun? Truly,  it  seems  as  if  there  could  be  no  new 
thing  under  the  sun. 


IX 

SCIENCE  OF  THE  ROMAN  PERIOD 

WE  have  seen  that  the  third  century  B.C.  was  a 
time  when  Alexandrian  science  was  at  its  height, 
but  that  the  second  century  produced  also  in  Hippar- 
chus  at  least  one  investigator  of  the  very  first  rank; 
though,  to  be  sure,  Hipparchus  can  be  called  an  Alex- 
andrian only  by  courtesy.  In  the  ensuing  generations 
the  Greek  capital  at  the  mouth  of  the  Nile  continued 
to  hold  its  place  as  the  centre  of  scientific  and  philo- 
sophical thought.  The  kingdom  of  the  Ptolemies  still 
flourished  with  at  least  the  outward  appearances  of 
its  old-time  glory,  and  a  company  of  grammarians  and 
commentators  of  no  small  merit  could  always  be  found 
in  the  service  of  the  famous  museum  and  library ;  but 
the  whole  aspect  of  world-history  was  rapidly  changing. 
Greece,  after  her  brief  day  of  political  supremacy,  was 
sinking  rapidily  into  desuetude,  and  the  hard-headed 
Roman  in  the  West  was  making  himself  master  every- 
where. While  Hipparchus  of  Rhodes  was  in  his  prime, 
Corinth,  the  last  stronghold  of  the  main -land  of  Greece, 
had  fallen  before  the  prowess  of  the  Roman,  and  the 
kingdom  of  the  Ptolemies,  though  still  nominally  free, 
had  begun  to  come  within  the  sphere  of  Roman  in- 
fluence. 

Just  what  share  these  political  changes  had  in  chang- 
ing the  aspect  of  Greek  thought  is  a  question  regarding 

253 


A    HISTORY   OF   SCIENCE 

which  difference  of  opinion  might  easily  prevail;  but 
there  can  be  no  question  that,  for  one  reason  or  another, 
the  Alexandrian  school  as  a  creative  centre  went  into 
a  rapid  decline  at  about  the  time  of  the  Roman  rise  to 
world-power.  There  are  some  distinguished  names, 
but,  as  a  general  rule,  the  spirit  of  the  times  is  remi- 
niscent rather  than  creative ;  the  workers  tend  to  collate 
the  researches  of  their  predecessors  rather  than  to  make 
new  and  original  researches  for  themselves.  Eratos- 
thenes, the  inventive  world-measurer,  was  succeeded 
by  Strabo,  the  industrious  collator  of  facts;  Aristar- 
chus  and  Hipparchus,  the  originators  of  new  astronom- 
ical methods,  were  succeeded  by  Ptolemy,  the  perfecter 
of  their  methods  and  the  systematizer  of  their  knowl- 
edge. Meanwhile,  in  the  West,  Rome  never  became  a 
true  culture-centre.  The  great  genius  of  the  Roman 
was  political;  the  Augustan  Age  produced  a  few  great 
historians  and  poets,  but  not  a  single  great  philosopher 
or  creative  devotee  of  science.  Cicero,  Lucian,  Seneca, 
Marcus  Aurelius,  give  us  at  best  a  reflection  of  Greek 
philosophy.  Pliny,  the  one  world-famous  name  in  the 
scientific  annals  of  Rome,  can  lay  claim  to  no  higher 
credit  than  that  of  a  marvellously  industrious  collector 
of  facts — the  compiler  of  an  encyclopaedia  which  con- 
tains not  one  creative  touch. 

All  in  all,  then,  this  epoch  of  Roman  domination  is 
one  that  need  detain  the  historian  of  science  but  a 
brief  moment.  With  the  culmination  of  Greek  effort 
in  the  so-called  Hellenistic  period  we  have  seen  an- 
cient science  at  its  climax.  The  Roman  period  is  but 
a  time  of  transition,  marking,  as  it  were,  a  plateau  on 
the  slope  between  those  earlier  heights  and  the  deep, 

254 


PLINY 
(From  an  old  print.) 


SCIENCE    OF   THE   ROMAN    PERIOD 

dark  valleys  of  the  Middle  Ages.  Yet  we  cannot 
quite  disregard  the  efforts  of  such  workers  as  those  we 
have  just  named.  Let  us  take  a  more  specific  glance 
at  their  accomplishments. 

STRABO   THE   GEOGRAPHER 

The  earliest  of  these  workers  in  point  of  time  is 
Strabo.  This  most  famous  of  ancient  geographers 
was  born  in  Amasia,  Pontus,  about  63  B.C.,  and  lived 
to  the  year  24  a.d.,  living,  therefore,  in  the  age  of 
Caesar  and  Augustus,  during  which  the  final  transfor- 
mation in  the  political  position  of  the  kingdom  of 
Egypt  was  effected.  The  name  of  Strabo  in  a  modi- 
fied form  has  become  popularized  through  a  curious 
circumstance.  The  geographer,  it  appears,  was  afflict- 
ed with  a  peculiar  squint  of  the  eyes,  hence  the  name 
strabismus,  which  the  modern  oculist  applies  to  that 
particular  infirmity. 

Fortunately,  the  great  geographer  has  not  been 
forced  to  depend  upon  hearsay  evidence  for  recogni- 
tion. His  comprehensive  work  on  geography  has 
been  preserved  in  its  entirety,  being  one  of  the  few  ex- 
pansive classical  writings  of  which  this  is  true.  The 
other  writings  of  Strabo,  however,  including  certain 
histories  of  which  reports  have  come  down  to  us,  are 
entirely  lost.  The  geography  is  in  many  ways  a  re- 
markable book.  It  is  not,  however,  a  work  in  which 
any  important  new  principles  are  involved.  Rather 
is  it  typical  of  its  age  in  that  it  is  an  elaborate  com- 
pilation and  a  critical  review  of  the  labors  of  Strabo' s 
predecessors.  Doubtless  it  contains  a  vast  deal  of  new 
information  as  to  the  details  of  geography — precise 

255 


A   HISTORY   OF   SCIENCE 

areas  and  distance,  questions  of  geographical  locations 
as  to  latitude  and  zones,  and  the  like.  But  however 
important  these  details  may  have  been  from  a  con- 
temporary stand-point,  they,  of  course,  can  have  noth- 
ing more  than  historical  interest  to  posterity.  The 
value  of  the  work  from  our  present  stand -point  is  chiefly 
due  to  the  criticisms  which  Strabo  passes  upon  his  fore- 
runners, and  to  the  incidental  historical  and  scien- 
tific references  with  which  his  work  abounds.  Being 
written  in  this  closing  period  of  ancient  progress,  and 
summarizing,  as  it  does,  in  full  detail  the  geographical 
knowledge  of  the  time,  it  serves  as  an  important 
guide-mark  for  the  student  of  the  progress  of  scientific 
thought.  We  cannot  do  better  than  briefly  to  follow 
Strabo  in  his  estimates  and  criticisms  of  the  work  of 
his  predecessors,  taking  note  thus  of  the  point  of  view 
from  which  he  himself  looked  out  upon  the  world. 
We  shall  thus  gain  a  clear  idea  as  to  the  state  of  scien- 
tific geography  towards  the  close  of  the  classical  epoch. 
"  If  the  scientific  investigation  of  any  subject  be  the 
proper  avocation  of  the  philosopher,"  says  Strabo, 
"geography,  the  science  of  which  we  propose  to  treat, 
is  certainly  entitled  to  a  high  place ;  and  this  is  evident 
from  many  considerations.  They  who  first  under- 
took to  handle  the  matter  were  distinguished  men. 
Homer,  Anaximander  the  Milesian,  and  Hecataeus  (his 
fellow-citizen  according  to  Eratosthenes),  Democritus, 
Eudoxus,  Dicaearchus,  and  Ephorus,  with  many 
others,  and  after  these,  Eratosthenes,  Polybius,  and 
Posidonius,  all  of  them  philosophers.  Nor  is  the 
great  learning  through  which  alone  this  subject  can  be 
approached  possessed  by  any  but  a  person  acquainted 

256 


SCIENCE   OF   THE   ROMAN   PERIOD 

with  both  human  and  divine  things,  and  these  attain- 
ments constitute  what  is  called  philosophy.  In  addi- 
tion to  its  vast  importance  in  regard  to  social  life  and 
the  art  of  government,  geography  unfolds  to  us  a  celes- 
tial phenomena,  acquaints  us  with  the  occupants  of 
the  land  and  ocean,  and  the  vegetation,  fruits,  and 
peculiarities  of  the  various  quarters  of  the  earth,  a 
knowledge  of  which  marks  him  who  cultivates  it  as 
a  man  earnest  in  the  great  problem  of  life  and  hap- 
piness." 

Strabo  goes  on  to  say  that  in  common  with  other 
critics,  including  Hipparchus,  he  regards  Homer  as  the 
first  great  geographer.  He  has  much  to  say  on  the 
geographical  knowledge  of  the  bard,  but  this  need  not 
detain  us.  We  are  chiefly  concerned  with  his  comment 
upon  his  more  recent  predecessors,  beginning  with 
Eratosthenes.  The  constant  reference  to  this  worker 
shows  the  important  position  which  he  held.  Strabo 
appears  neither  as  detractor  nor  as  partisan,  but  as  one 
who  earnestly  desires  the  truth.  Sometimes  he  seems 
captious  in  his  criticisms  regarding  some  detail,  nor  is 
he  always  correct  in  his  emendations  of  the  labors  of 
others;  but,  on  the  whole,  his  work  is  marked  by  an 
evident  attempt  at  fairness.  In  reading  his  book, 
however,  one  is  forced  to  the  conclusion  that  Strabo  is 
an  investigator  of  details,  not  an  original  thinker.  He 
seems  more  concerned  with  precise  measurements  than 
with  questionings  as  to  the  open  problems  of  his  science. 
Whatever  he  accepts,  then,  may  be  taken  as  virtually 
the  stock  doctrine  of  the  period. 

"  As  the  size  of  the  earth,"  he  says,  "  has  been  demon- 
strated by  other  writers,  we  shall  here  take  for  granted 

VOL.  I.— 17  257 


A   HISTORY   OF   SCIENCE 

and  receive  as  accurate  what  they  have  advanced.  We 
shall  also  assume  that  the  earth  is  spheroidal,  that  its 
surface  is  likewise  spheroidal  and,  above  all,  that  bodies 
have  a  tendency  towards  its  centre,  which  latter  point 
is. clear  to  the  perception  of  the  most  average  under- 
standing. However,  we  may  show  summarily  that 
the  earth  is  spheroidal,  from  the  consideration  that  all 
things,  however  distant,  tend  to  its  centre,  and  that 
every  body  is  attracted  towards  its  centre  by  gravity. 
This  is  more  distinctly  proved  from  observations  of 
the  sea  and  sky,  for  here  the  evidence  of  the  senses  and 
common  observation  is  alone  requisite.  The  con- 
vexity of  the  sea  is  a  further  proof  of  this  to  those  who 
have  sailed,  for  they  cannot  perceive  lights  at  a  dis- 
tance when  placed  at  the  same  level  as  their  eyes,  and 
if  raised  on  high  they  at  once  become  perceptible  to 
vision  though  at  the  same  time  farther  removed.  So 
when  the  eye  is  raised  it  sees  what  before  was  utterly 
imperceptible.     Homer  speaks  of  this  when  he  says : 

"  '  Lifted  up  on  the  vast  wave  he  quickly  beheld  afar.' 

Sailors  as  they  approach  their  destination  behold  the 
shore  continually  raising  itself  to  their  view,  and  ob- 
jects which  had  at  first  seemed  low  begin  to  lift  them- 
selves. Our  gnomons,  also,  are,  among  other  things, 
evidence  of  the  revolution  of  the  heavenly  bodies,  and 
common-sense  at  once  shows  us  that  if  the  depth  of  the 
earth  were  infinite  such  a  revolution  could  not  take 
place."  * 

Elsewhere  Strabo  criticises  Eratosthenes  for  having 
entered  into  a  long  discussion  as  to  the  form  of  the 

258 


SCIENCE   OF   THE    ROMAN    PERIOD 

earth.  This  matter,  Strabo  thinks,  "should  have  been 
disposed  of  in  the  compass  of  a  few  words. ' '  Obviously 
this  doctrine  of  the  globe's  sphericity  had,  in  the  course 
of  600  years,  become  so  firmly  established  among  the 
Greek  thinkers  as  to  seem  almost  axiomatic.  We 
shall  see  later  on  how  the  Western  world  made  a  curi- 
ous recession  from  this  seemingly  secure  position  under 
stimulus  of  an  Oriental  misconception.  As  to  the  size 
of  the  globe,  Strabo  is  disposed  to  accept  without  par- 
ticular comment  the  measurements  of  Eratosthenes. 
He  speaks,  however,  of  "more  recent  measurements," 
referring  in  particular  to  that  adopted  by  Posidonius, 
according  to  which  the  circumference  is  only  about 
one  hundred  and  eighty  thousand  stadia.  Posidonius, 
we  may  note  in  passing,  was  a  contemporary  and 
friend  of  Cicero,  and  hence  lived  shortly  before  the 
time  of  Strabo.  His  measurement  of  the  earth  was 
based  on  observations  of  a  star  which  barely  rose  above 
the  southern  horizon  at  Rhodes  as  compared  with  the 
height  of  the  same  star  when  observed  at  Alexandria. 
This  measurement  of  Posidonius,  together  with  the 
even  more  famous  measurement  of  Eratosthenes,  ap- 
pears to  have  been  practically  the  sole  guide  as  to  the 
size  of  the  earth  throughout  the  later  periods  of  an- 
tiquity, and,  indeed,  until  the  later  Middle  Ages. 

As  becomes  a  writer  who  is  primarily  geographer  and 
historian  rather  than  astronomer,  Strabo  shows  a 
much  keener  interest  in  the  habitable  portions  of  the 
globe  than  in  the  globe  as  a  whole.  He  assures  us  that 
this  habitable  portion  of  the  earth  is  a  great  island, 
"  since  wherever  men  have  approached  the  termination 
of  the  land,  the  sea,  which  we  designate  ocean,  has 

259 


A    HISTORY    OF   SCIENCE 

been  met  with,  and  reason  assures  us  of  the  similarity 
of  this  place  which  our  senses  have  not  been  tempted 
to  survey."  He  points  out  that  whereas  sailors  have 
not  circumnavigated  the  globe,  that  they  had  not  been 
prevented  from  doing  so  by  any  continent,  and  it  seems 
to  him  altogether  unlikely  that  the  Atlantic  Ocean  is 
divided  into  two  seas  by  narrow  isthmuses  so  placed  as 
to  prevent  circumnavigation.  ' '  How  much  more  prob- 
able that  it  is  confluent  and  uninterrupted.  This 
theory,"  he  adds,  "goes  better  with  the  ebb  and  flow 
of  the  ocean.  Moreover  (and  here  his  reasoning  be- 
comes more  fanciful) ,  the  greater  the  amount  of  moist- 
ure surrounding  the  earth,  the  easier  would  the  heaven- 
ly bodies  be  supplied  with  vapor  from  thence."  Yet 
he  is  disposed  to  believe,  following  Plato,  that  the 
tradition  "concerning  the  island  of  Atlantos  might  be 
received  as  something  more  than  idle  fiction,  it  having 
been  related  by  Solon,  on  the  authority  of  the  Egyptian 
priests,  that  this  island,  almost  as  large  as  a  continent, 
was  formerly  in  existence  although  now  it  had  disap- 
peared."2 

In  a  word,  then,  Strabo  entertains  no  doubt  what- 
ever that  it  would  be  possible  to  sail  around  the  globe 
from  Spain  to  India.  Indeed,  so  matter-of-fact  an  in- 
ference was  this  that  the  feat  of  Columbus  would  have 
seemed  less  surprising  in  the  first  century  of  our  era 
than  it  did  when  actually  performed  in  the  fifteenth 
century.  The  terrors  of  the  great  ocean  held  the  mar- 
iner back,  rather  than  any  doubt  as  to  where  he  would 
arrive  at  the  end  of  the  voyage. 

Coupled  with  the  idea  that  the  habitable  portion  of 
the  earth  is  an  island,  there  was  linked  a  tolerably 

260 


SCIENCE   OF   THE   ROMAN    PERIOD 

definite  notion  as  to  the  shape  of  this  island.  This 
shape  Strabo  likens  to  a  military  cloak.  The  compari- 
son does  not  seem  peculiarly  apt  when  we  are  told 
presently  that  the  length  of  the  habitable  earth  is  more 
than  twice  its  breadth.  This  idea,  Strabo  assures  us, 
accords  with  the  most  accurate  observations  "both 
ancient  and  modern."  These  observations  seemed  to 
show  that  it  is  not  possible  to  live  in  the  region  close 
to  the  equator,  and  that,  on  the  other  hand,  the  cold 
temperature  sharply  limits  the  habitability  of  the  globe 
towards  the  north.  All  the  civilization  of  antiquity 
clustered  about  the  Mediterranean,  or  extended  off 
towards  the  east  at  about  the  same  latitude.  Hence 
geographers  came  to  think  of  the  habitable  globe  as 
having  the  somewhat  lenticular  shape  which  a  crude 
map  of  these  regions  suggests.  We  have  already  had 
occasion  to  see  that  at  an  earlier  day  Anaxagoras 
was  perhaps  influenced  in  his  conception  of  the  shape 
of  the  earth  by  this  idea,  and  the  constant  refer- 
ences of  Strabo  impress  upon  us  the  thought  that  this 
long,  relatively  narrow  area  of  the  earth's  surface 
is  the  only  one  which  can  be  conceived  of  as  hab- 
itable. 

Strabo  had  much  to  tell  us  concerning  zones,  which, 
following  Posidonius,  he  believes  to  have  been  first 
described  by  Parmenides.  We  may  note,  however, 
that  other  traditions  assert  that  both  Thales  and  Py- 
thagoras had  divided  the  earth  into  zones.  The  num- 
ber of  zones  accepted  by  Strabo  is  five,  and  he  criticises 
Polybius  for  making  the  number  six.  The  five  zones 
accepted  by  Strabo  are  as  follows:  the  uninhabitable 
torrid  zone  lying  in  the  region  of  the  equator ;  a  zone  on 

261 


A   HISTORY   OF   SCIENCE 

either  side  of  this  extending  to  the  tropic;  and  then 
the  temperate  zones  extending  in  either  direction  from 
the  tropic  to  the  arctic  regions.  There  seems  to  have 
been  a  good  deal  of  dispute  among  the  scholars  of  the 
time  as  to  the  exact  arrangement  of  these  zones,  but  the 
general  idea  that  the  north-temperate  zone  is  the  part 
of  the  earth  with  which  the  geographer  deals  seemed 
clearly  established.  That  the  south-temperate  zone 
would  also  present  a  habitable  area  is  an  idea  that  is 
sometimes  suggested,  though  seldom  or  never  distinctly 
expressed.  It  is  probable  that  different  opinions  were 
held  as  to  this,  and  no  direct  evidence  being  available, 
a  cautiously  scientific  geographer  like  Strabo  would 
naturally  avoid  the  expression  of  an  opinion  regarding 
it.  Indeed,  his  own  words  leave  us  somewhat  in 
doubt  as  to  the  precise  character  of  his  notion  regard- 
ing the  zones.  Perhaps  we  shall  do  best  to  quote 
them: 

"  Let  the  earth  be  supposed  to  consist  of  five  zones, 
(i)  The  equatorial  circle  described  around  it.  (2)  An- 
other parallel  to  this,  and  defining  the  frigid  zone  of  the 
northern  hemisphere.  (3)  A  circle  passing  through 
the  poles  and  cutting  the  two  preceding  circles  at  right- 
angles.  The  northern  hemisphere  contains  two  quar- 
ters of  the  earth,  which  are  bounded  by  the  equator 
and  circle  passing  through  the  poles.  Each  of  these 
quarters  should  be  supposed  to  contain  a  four-sided 
district,  its  northern  side  being  of  one-half  of  the  par- 
allel next  the  pole,  its  southern  by  the  half  of  the  equa- 
tor, and  its  remaining  sides  by  two  segments  of  the  circle 
drawn  through  the  poles,  opposite  to  each  other,  and 
equal  in  length.     In  one  of  these  (which  of  them  is  of 

262 


SCIENCE   OF   THE   ROMAN    PERIOD 

no  consequence)  the  earth  which  we  inhabit  is  situated, 
surrounded  by  a  sea  and  similar  to  an  island.  This, 
as  we  said  before,  is  evident  both  to  our  senses  and  to 
our  reason.  But  let  any  one  doubt  this,  it  makes  no 
difference  so  far  as  geography  is  concerned  whether  you 
believe  the  portion  of  the  earth  which  we  inhabit  to  be 
an  island  or  only  admit  what  we  know  from  experience 
— namely,  that  whether  you  start  from  the  east  or  the 
west  you  may  sail  all  around  it.  Certain  intermediate 
spaces  may  have  been  left  (unexplored),  but  these  are 
as  likely  to  be  occupied  by  sea  as  uninhabited  land. 
The  object  of  the  geographer  is  to  describe  known 
countries.  Those  which  are  unknown  he  passes  over 
equally  with  those  beyond  the  limits  of  the  inhabited 
earth.  It  will,  therefore,  be  sufficient  for  describing 
the  contour  of  the  island  we  have  been  speaking  of,  if  we 
join  by  a  right  line  the  outmost  points  which,  up  to  this 
time,  have  been  explored  by  voyagers  along  the  coast 
on  either  side."  3 

We  may  pass  over  the  specific  criticisms  of  Strabo 
upon  various  explorations  that  seem  to  have  been  of 
great  interest  to  his  contemporaries,  including  an 
alleged  trip  of  one  Eudoxus  out  into  the  Atlantic,  and 
the  journeyings  of  Pytheas  in  the  far  north.  It  is 
Pytheas,  we  may  add,  who  was  cited  by  Hipparchus 
as  having  made  the  mistaken  observation  that  the 
length  of  the  shadow  of  the  gnomon  is  the  same  at 
Marseilles  and  Byzantium,  hence  that  these  two  places 
are  on  the  same  parallel.  Modern  commentators  have 
defended  Pytheas  as  regards  this  observation,  claiming 
that  it  was  Hipparchus  and  not  Pytheas  who  made  the 
second  observation  from  which  the  faulty  induction 

263 


A   HISTORY   OF   SCIENCE 

was  drawn.  The  point  is  of  no  great  significance, 
however,  except  as  showing  that  a  correct  method  of 
determining  the  problems  of  latitude  had  thus  early- 
been  suggested.  That  faulty  observations  and  faulty 
application  of  the  correct  principle  should  have  been 
made  is  not  surprising.  Neither  need  we  concern 
ourselves  with  the  details  as  to  the  geographical  dis- 
tances, which  Strabo  found  so  worthy  of  criticism  and 
controversy.  But  in  leaving  the  great  geographer 
we  may  emphasize  his  point  of  view  and  that  of  his 
contemporaries  by  quoting  three  fundamental  prin- 
ciples which  he  reiterates  as  being  among  the  "facts 
established  by  natural  philosophers."  He  tells  us 
that  "  (i)  The  earth  and  heavens  are  spheroidal.  (2) 
The  tendency  of  all  bodies  having  weight  is  towards  a 
centre.  (3)  Further,  the  earth  being  spheroidal  and 
having  the  same  centre  as  the  heavens,  is  motionless,  as 
well  as  the  axis  that  passes  through  both  it  and  the 
heavens.  The  heavens  turn  round  both  the  earth  and 
its  axis,  from  east  to  west.  The  fixed  stars  turn  round 
with  it  at  the  same  rate  as  the  whole.  These  fixed 
stars  follow  in  their  course  parallel  circles,  the  principal 
of  which  are  the  equator,  two  tropics,  and  the  arctic 
circles;  while  the  planets,  the  sun,  and  the  moon  de- 
scribe certain  circles  comprehended  within  the  zo- 
diac."4 

Here,  then,  is  a  curious  mingling  of  truth  and  error. 
The  Pythagorean  doctrine  that  the  earth  is  round  had 
become  a  commonplace,  but  it  would  appear  that  the 
theory  of  Aristarchus,  according  to  which  the  earth 
is  in  motion,  has  been  almost  absolutely  forgotten. 
Strabo  does  not  so  much  as  refer  to  it;  neither,  as  we 

264 


SCIENCE   OF   THE   ROMAN    PERIOD 

shall  see,  is  it  treated  with  greater  respect  by  the  other 
writers  of  the  period. 

TWO    FAMOUS    EXPOSITORS — PLINY    AND    PTOLEMY 

While  Strabo  was  pursuing  his  geographical  studies 
at  Alexandria,  a  young  man  came  to  Rome  who  was 
destined  to  make  his  name  more  widely  known  in 
scientific  annals  than  that  of  any  other  Latin  writer 
of  antiquity.  This  man  was  Plinius  Secundus,  who, 
to  distinguish  him  from  his  nephew,  a  famous  writer 
in  another  field,  is  usually  spoken  of  as  Pliny  the  Elder. 
There  is  a  famous  story  to  the  effect  that  the  great 
Roman  historian  Livy  on  one  occasion  addressed  a 
casual  associate  in  the  amphitheatre  at  Rome,  and  on 
learning  that  the  stranger  hailed  from  the  outlying 
Spanish  province  of  the  empire,  remarked  to  him, 
"Yet  you  have  doubtless  heard  of  my  writings  even 
there."  "Then,"  replied  the  stranger,  "you  must  be 
either  Livy  or  Pliny." 

The  anecdote  illustrates  the  wide  fame  which  the 
Roman  naturalist  achieved  in  his  own  day.  And  the 
records  of  the  Middle  Ages  show  that  this  popularity 
did  not  abate  in  succeeding  times.  Indeed,  the  Natural 
History  of  Pliny  is  one  of  the  comparatively  few  bulky 
writings  of  antiquity  that  the  efforts  of  copyists  have 
preserved  to  us  almost  entire.  It  is,  indeed,  a  remark- 
able work  and  eminently  typical  of  its  time;  but 
its  author  was  an  industrious  compiler,  not  a  creative 
genius.  As  a  monument  of  industry  it  has  seldom 
been  equalled,  and  in  this  regard  it  seems  the  more 
remarkable  inasmuch  as  Pliny  was  a  practical  man  of 
affairs  who  occupied  most  of  his  life  as  a  soldier  fight- 

265 


A   HISTORY   OF  SCIENCE 

ing  the  battles  of  the  empire.  He  compiled  his  book 
in  the  leisure  hours  stolen  from  sleep,  often  writing  by 
the  light  of  the  camp-fire.  Yet  he  cites  or  quotes  from 
about  four  thousand  works,  most  of  which  are  known 
to  us  only  by  his  references.  Doubtless  Pliny  added 
much  through  his  own  observations.  We  know  how 
keen  was  his  desire  to  investigate,  since  he  lost  his  life 
through  attempting  to  approach  the  crater  of  Vesu- 
vius on  the  occasion  of  that  memorable  eruption  which 
buried  the  cities  of  Herculaneum  and  Pompeii. 

Doubtless  the  wandering  life  of  the  soldier  had  given 
Pliny  abundant  opportunity  for  personal  observation  in 
his  favorite  fields  of  botany  and  zoology.  But  the  rec- 
ords of  his  own  observations  are  so  intermingled  with 
knowledge  drawn  from  books  that  it  is  difficult  to  dis- 
tinguish the  one  from  the  other.  Nor  does  this  greatly 
matter,  for  whether  as  closet-student  or  field-natural- 
ist, Pliny's  trait  of  mind  is  essentially  that  of  the  com- 
piler. He  was  no  philosophical  thinker,  no  generalizer, 
no  path-maker  in  science.  He  lived  at  the  close  of  a 
great  progressive  epoch  of  thought;  in  one  of  those 
static  periods  when  numberless  observers  piled  up  an 
immense  mass  of  details  which  might  advantageously 
be  sorted  into  a  kind  of  encyclopaedia.  Such  an  en- 
cyclopaedia is  the  so-called  Natural  History  of  Pliny. 
It  is  a  vast  jumble  of  more  or  less  uncritical  statements 
regarding  almost  every  field  of  contemporary  knowl- 
edge. The  descriptions  of  animals  and  plants  pre- 
dominate, but  the  work  as  a  whole  would  have  been  im- 
mensely improved  had  the  compiler  shown  a  more 
critical  spirit.  As  it  is,  he  seems  rather  disposed  to 
quote  any  interesting  citation  that  he  comes  across  in 

266 


SCIENCE   OF   THE   ROMAN    PERIOD 

his  omnivorous  readings,  shielding  himself  behind  an 
equivocal  "it  is  said,"  or  "so  and  so  alleges."  A  sin- 
gle illustration  will  suffice  to  show  what  manner  of 
thing  is  thought  worthy  of  repetition. 

"It  is  asserted,"  he  says,  "that  if  the  fish  called  a 
sea-star  is  smeared  with  the  fox's  blood  and  then  nailed 
to  the  upper  lintel  of  the  door,  or  to  the  door  itself,  with 
a  copper  nail,  no  noxious  spell  will  be  able  to  obtain 
admittance,  or,  at  all  events,  be  productive  of  any  ill 
effects." 

It  is  easily  comprehensible  that  a  work  fortified 
with  such  practical  details  as  this  should  have  gained 
wide  popularity.  Doubtless  the  natural  histories  of 
our  own  day  would  find  readier  sale  were  they  to  pan- 
der to  various  superstitions  not  altogether  different 
from  that  here  suggested.  The  man,  for  example,  who 
believes  that  to  have  a  black  cat  cross  his  path  is  a 
lucky  omen  would  naturally  find  himself  attracted  by  a 
book  which  took  account  of  this  and  similar  important 
details  of  natural  history.  Perhaps,  therefore,  it  was 
its  inclusion  of  absurdities,  quite  as  much  as  its  legiti- 
mate value,  that  gave  vogue  to  the  celebrated  work 
of  Pliny.  But  be  that  as  it  may,  the  most  famous 
scientist  of  Rome  must  be  remembered  as  a  popular 
writer  rather  than  as  an  experimental  worker.  In  the 
history  of  the  promulgation  of  scientific  knowledge  his 
work  is  important;  in  the  history  of  scientific  princi- 
ples it  may  virtually  be  disregarded. 

PTOLEMY,  THE  LAST  GREAT  ASTRONOMER  OP  ANTIQUITY 

Almost  the  same  thing  may  be  said  of  Ptolemy,  an 
even  more  celebrated  writer,  who  was  born  not  very 

267 


A   HISTORY   OF   SCIENCE 

long  after  the  death  of  Pliny.  The  exact  dates  of 
Ptolemy's  life  are  not  known,  but  his  recorded  ob- 
servations extend  to  the  year  151  a.d.  He  was  a 
working  astronomer,  and  he  made  at  least  one  origi- 
nal discovery  of  some  significance — namely,  the  obser- 
vation of  a  hitherto  unrecorded  irregularity  of  the 
moon's  motion,  which  came  to  be  spoken  of  as  the 
moon's  evection.  This  consists  of  periodical  aberra- 
tions from  the  moon's  regular  motion  in  its  orbit, 
which,  as  we  now  know,  are  due  to  the  gravitation  pull 
of  the  sun,  but  which  remained  unexplained  until  the 
time  of  Newton.  Ptolemy  also  made  original  observa- 
tions as  to  the  motions  of  the  planets.  He  is,  therefore, 
entitled  to  a  respectable  place  as  an  observing  astrono- 
mer ;  but  his  chief  fame  rests  on  his  writings. 

His  great  works  have  to  do  with  geography  and  as- 
tronomy. In  the  former  field  he  makes  an  advance 
upon  Strabo,  citing  the  latitude  of  no  fewer  than  five 
thousand  places.  In  the  field  of  astronomy,  his  great 
service  was  to  have  made  known  to  the  world  the  labors 
of  Hipparchus.  Ptolemy  has  been  accused  of  taking 
the  star-chart  of  his  great  predecessor  without  due 
credit,  and  indeed  it  seems  difficult  to  clear  him  of  this 
charge.  Yet  it  is  at  least  open  to  doubt  whether  he 
intended  any  impropriety,  inasmuch  as  he  all  along  is 
sedulous  in  his  references  to  his  predecessor.  Indeed, 
his  work  might  almost  be  called  an  exposition  of  the 
astronomical  doctrines  of  Hipparchus.  No  one  pre- 
tends that  Ptolemy  is  to  be  compared  with  the  Rho- 
desian  observer  as  an  original  investigator,  but  as  a 
popular  expounder  his  superiority  is  evidenced  in  the 
fact  that  the  writings  of  Ptolemy  became  practically 

268 


PTOLEMY 
(From  an  old  print.) 


SCIENCE   OF   THE   ROMAN    PERIOD 

the  sole  astronomical  text-book  of  the  Middle  Ages 
both  in  the  East  and  in  the  West,  while  the  writings 
of  Hipparchus  were  allowed  to  perish. 

The  most  noted  of  all  the  writings  of  Ptolemy  is  the 
work  which  became  famous  under  the  Arabic  name  of 
Almagest.  This  word  is  curiously  derived  from  the 
Greek  title  rj  /xeylarr}  crvvra^Ls,  "the  greatest  construc- 
tion," a  name  given  the  book  to  distinguish  it  from  a 
work  on  astrology  in  four  books  by  the  same  author. 
For  convenience  of  reference  it  came  to  be  spoken  of 
merely  as  r/  fieyia-rij,  from  which  the  Arabs  form  the 
title  Tabair  al  Magisthi,  under  which  title  the  book  was 
published  in  the  year  827.  From  this  it  derived  the 
word  Almagest,  by  which  Ptolemy's  work  continued 
to  be  known  among  the  Arabs,  and  subsequently  among 
Europeans  when  the  book  again  became  known  in  the 
West.  Ptolemy's  book,  as  has  been  said,  is  virtually 
an  elaboration  of  the  doctrines  of  Hipparchus.  It  as- 
sumes that  the  earth  is  the  fixed  centre  of  the  solar 
system,  and  that  the  stars  and  planets  revolve  about 
it  in  twenty-four  hours,  the  earth  being,  of  course, 
spherical.  It  was  not  to  be  expected  that  Ptolemy 
should  have  adopted  the  heliocentric  idea  of  Aristar- 
chus.  Yet  it  is  much  to  be  regretted  that  he  failed  to 
do  so,  since  the  deference  which  was  accorded  his  au- 
thority throughout  the  Middle  Ages  would  doubtless 
have  been  extended  in  some  measure  at  least  to  this 
theory  as  well,  had  he  championed  it.  Contrariwise, 
his  unqualified  acceptance  of  the  geocentric  doctrine 
sufficed  to  place  that  doctrine  beyond  the  range  of 
challenge. 

The  Almagest  treats  of  all  manner  of  astronomical 

269 


A   HISTORY    OF   SCIENCE 

problems,  but  the  feature  of  it  which  gained  it  widest 
celebrity  was  perhaps  that  which  has  to  do  with  ec- 
centrics and  epicycles.  This  theory  was,  of  course,  but 
an  elaboration  of  the  ideas  of  Hipparchus ;  but,  owing 
to  the  celebrity  of  the  expositor,  it  has  come  to  be 
spoken  of  as  the  theory  of  Ptolemy.  We  have  suf- 
ficiently detailed  the  theory  in  speaking  of  Hippar- 
chus. It  should  be  explained,  however,  that,  with 
both  Hipparchus  and  Ptolemy,  the  theory  of  epicycles 
would  appear  to  have  been  held  rather  as  a  working 
hypothesis  than  as  a  certainty,  so  far  as  the  actuality 
of  the  minor  spheres  or  epicycles  is  concerned.  That 
is  to  say,  these  astronomers  probably  did  not  conceive 
either  the  epicycles  or  the  greater  spheres  as  constitut- 
ing actual  solid  substances.  Subsequent  generations, 
however,  put  this  interpretation  upon  the  theory, 
conceiving  the  various  spheres  as  actual  crystalline 
bodies.  It  is  difficult  to  imagine  just  how  the  various 
epicycles  were  supposed  to  revolve  without  interfering 
with  the  major  spheres,  but  perhaps  this  is  no  greater 
difficulty  than  is  presented  by  the  alleged  properties 
of  the  ether,  which  physicists  of  to-day  accept  as  at 
least  a  working  hypothesis.  We  shall  see  later  on  how 
firmly  the  conception  of  concentric  crystalline  spheres 
was  held  to,  and  that  no  real  challenge  was  ever  given 
that  theory  until  the  discovery  was  made  that  comets 
have  an  orbit  that  must  necessarily  intersect  the 
spheres  of  the  various  planets. 

Ptolemy's  system  of  geography  in  eight  books, 
founded  on  that  of  Marinus  of  Tyre,  was  scarcely  less 
celebrated  throughout  the  Middle  Ages  than  the  Al- 
magest.    It  contained  little,  however,  that  need  con- 

270 


SCIENCE   OF   THE    ROMAN    PERIOD 

cern  us  here,  being  rather  an  elaboration  of  the  doc- 
trines to  which  we  have  already  sufficiently  referred. 
None  of  Ptolemy's  original  manuscripts  has  come 
down  to  us,  but  there  is  an  alleged  fifth-century  manu- 
script attributed  to  Agathadamon  of  Alexandria  which 
has  peculiar  interest  because  it  contains  a  series  of 
twenty-seven  elaborately  colored  maps  that  are  sup- 
posed to  be  derived  from  maps  drawn  up  by  Ptolemy 
himself.  In  these  maps  the  sea  is  colored  green,  the 
mountains  red  or  dark  yellow,  and  the  land  white. 
Ptolemy  assumed  that  a  degree  at  the  equator  was 
500  stadia  instead  of  604  stadia  in  length.  We  are  not 
informed  as  to  the  grounds  on  which  this  assumption 
was  made,  but  it  has  been  suggested  that  the  error  was 
at  least  partially  instrumental  in  leading  to  one  very 
curious  result.  "Taking  the  parallel  of  Rhodes,"  says 
Donaldson,5  "he  calculated  the  longitudes  from  the 
Fortunate  Islands  to  Cattigara  or  the  west  coast  of 
Borneo  at  1800,  conceiving  this  to  be  one-half  the  cir- 
cumference of  the  globe.  The  real  distance  is  only  1 250 
or  1 2  70,  so  that  his  measurement  is  wrong  by  one- 
third  of  the  whole,  one-sixth  for  the  error  in  the  meas- 
urement of  a  degree  and  one -sixth  for  the  errors  in 
measuring  the  distance  geometrically.  These  errors, 
owing  to  the  authority  attributed  to  the  geography  of 
Ptolemy  in  the  Middle  Ages,  produced  a  consequence 
of  the  greatest  importance.  They  really  led  to  the  dis- 
covery of  America.  For  the  design  of  Columbus  to  sail 
from  the  west  of  Europe  to  the  east  of  Asia  was  founded 
on  the  supposition  that  the  distance  was  less  by  one- 
third  than  it  really  was."  This  view  is  perhaps  a  trifle 
fanciful,  since  there  is  nothing  to  suggest  that  the  cour- 

271 


A   HISTORY   OF   SCIENCE 

age  of  Columbus  would  have  balked  at  the  greater  dis- 
tance, and  since  the  protests  of  the  sailors,  which 
nearly  thwarted  his  efforts,  were  made  long  before  the 
distance  as  estimated  by  Ptolemy  had  been  covered; 
nevertheless  it  is  interesting  to  recall  that  the  great  geo- 
graphical doctrines,  upon  which  Columbus  must  chiefly 
have  based  his  arguments,  had  been  before  the  world 
in  an  authoritative  form  practically  unheeded  for  more 
than  twelve  hundred  years,  awaiting  a  champion  with 
courage  enough  to  put  them  to  the  test. 

GALEN — THE  LAST  GREAT  ALEXANDRIAN 

There  is  one  other  field  of  scientific  investigation  to 
which  we  must  give  brief  attention  before  leaving  the 
antique  world.  This  is  the  field  of  physiology  and 
medicine.  In  considering  it  we  shall  have  to  do  with 
the  very  last  great  scientist  of  the  Alexandrian  school. 
This  was  Claudius  Galenus,  commonly  known  as  Galen, 
a  man  whose  fame  was  destined  to  eclipse  that  of  all 
other  physicians  of  antiquity  except  Hippocrates,  and 
whose  doctrines  were  to  have  the  same  force  in  their 
field  throughout  the  Middle  Ages  that  the  doctrines 
of  Aristotle  had  for  physical  science.  But  before  we 
take  up  Galen's  specific  labors,  it  will  be  well  to  inquire 
briefly  as  to  the  state  of  medical  art  and  science  in  the 
Roman  world  at  the  time  when  the  last  great  physician 
of  antiquity  came  upon  the  scene. 

The  Romans,  it  would  appear,  had  done  little  in  the 
way  of  scientific  discoveries  in  the  field  of  medicine,  but, 
nevertheless,  with  their  practicality  of  mind,  they  had 
turned  to  better  account  many  more  of  the  scientific 
discoveries  of  the  Greeks  than  did  the  discoverers  them- 
,     272 


SCIENCE   OF   THE   ROMAN    PERIOD 

selves.  The  practising  physicians  in  early  Rome  were 
mostly  men  of  Greek  origin,  who  came  to  the  capital 
after  the  overthrow  of  the  Greeks  by  the  Romans. 
Many  of  them  were  slaves,  as  earning  money  by  either 
bodily  or  mental  labor  was  considered  beneath  the 
dignity  of  a  Roman  citizen.  The  wealthy  Romans, 
who  owned  large  estates  and  numerous  slaves,  were  in 
the  habit  of  purchasing  some  of  these  slave  doctors, 
and  thus  saving  medical  fees  by  having  them  attend  to 
the  health  of  their  families. 

By  the  beginning  of  the  Christian  era  medicine  as  a 
profession  had  sadly  degenerated,  and  in  place  of  a 
class  of  physicians  who  practised  medicine  along  ra- 
tional or  legitimate  lines,  in  the  footsteps  of  the  great 
Hippocrates,  there  appeared  great  numbers  of  "  spe- 
cialists," most  of  them  charlatans,  who  pretended  to 
possess  supernatural  insight  in  the  methods  of  treat- 
ing certain  forms  of  disease.  These  physicians  rightly 
earned  the  contempt  of  the  better  class  of  Romans,  and 
were  made  the  object  of  many  attacks  by  the  satirists 
of  the  time.  Such  specialists  travelled  about  from 
place  to  place  in  much  the  same  manner  as  the  itiner- 
ant "  Indian  doctors  "  and  "  lightning  tooth-extractors  " 
do  to-day.  Eye-doctors  seem  to  have  been  particu- 
larly numerous,  and  these  were  divided  into  two  classes, 
eye-surgeons  and  eye-doctors  proper.  The  eye-sur- 
geon performed  such  operations  as  cauterizing  for  in- 
growing eyelashes  and  operating  upon  growths  about 
the  eyes ;  while  the  eye-doctors  depended  entirely  upon 
salves  and  lotions.  These  eye-salves  were  frequently 
stamped  with  the  seal  of  the  physician  who  compound- 
ed them,  something  like  two  hundred  of  these  seals 

VOL.  I.— 1 8  2  73 


A    HISTORY    OF   SCIENCE 

being  still  in  existence.  There  were  besides  these 
quacks,  however,  reputable  eye-doctors  who  must  have 
possessed  considerable  skill  in  the  treatment  of  certain 
ophthalmias.  Among  some  Roman  surgical  instru- 
ments discovered  at  Rheims  were  found  also  some 
drugs  employed  by  ophthalmic  surgeons,  and  an  anal- 
ysis of  these  show  that  they  contained,  among  other 
ingredients,  some  that  are  still  employed  in  the  treat- 
ment of  certain  affections  of  the  eye. 

One  of  the  first  steps  taken  in  recognition  of  the  ser- 
vices of  physicians  was  by  Julius  Cassar,  who  granted 
citizenship  to  all  physicians  practising  in  Rome.  This 
was  about  fifty  years  before  the  Christian  era,  and 
from  that  time  on  there  was  a  gradual  improvement 
in  the  attitude  of  the  Romans  towards  the  members  of 
the  medical  profession.  As  the  Romans  degenerated 
from  a  race  of  sturdy  warriors  and  became  more  and 
more  depraved  physically,  the  necessity  for  physicians 
made  itself  more  evident.  Court  physicians,  and  phy- 
sicians-in-ordinary,  were  created  by  the  emperors,  as 
were  also  city  and  district  physicians.  In  the  year 
133  a.d.  Hadrian  granted  immunity  from  taxes  and 
military  service  to  physicians  in  recognition  of  their 
public  services. 

The  city  and  district  physicians,  known  as  the  archi- 
atri  populaires,  treated  and  cared  for  the  poor  without 
remuneration,  having  a  position  and  salary  fixed  by 
law  and  paid  them  semi-annually.  These  were  hon- 
orable positions,  and  the  archiatri  were  obliged  to  give 
instruction  in  medicine,  without  pay,  to  the  poor 
students.  They  were  allowed  to  receive  fees  and  do- 
nations from  their  patients,  but  not,  however,  until  the 

274 


SCIENCE   OF   THE   ROMAN    PERIOD 

danger  from  the  malady  was  past.  Special  laws  were 
enacted  to  protect  them,  and  any  person  subjecting 
them  to  an  insult  was  liable  to  a  fine  "  not  exceeding 
one  thousand  pounds." 

An  example  of  Roman  practicality  is  shown  in  the 
method  of  treating  hemorrhage,  as  described  by  Aulus 
Cornelius  Celsus  (53  B.C.  to  7  a.d.).  Hippocrates  and 
Hippocratic  writers  treated  hemorrhage  by  applica- 
tion of  cold,  pressure,  styptics,  and  sometimes  by  actual 
cauterizing;  but  they  knew  nothing  of  the  simple 
method  of  stopping  a  hemorrhage  by  a  ligature  tied 
around  the  bleeding  vessel.  Celsus  not  only  recom- 
mended tying  the  end  of  the  injured  vessel,  but  de- 
scribes the  method  of  applying  two  ligatures  before 
the  artery  is  divided  by  the  surgeon — a  common  prac- 
tice among  surgeons  at  the  present  time.  The  cut  is 
made  between  these  two,  and  thus  hemorrhage  is 
avoided  from  either  end  of  the  divided  vessel. 

Another  Roman  surgeon,  Heliodorus,  not  only  de- 
scribes the  use  of  the  ligature  in  stopping  hemorrhage, 
but  also  the  practice  of  torsion — twisting  smaller  ves- 
sels, which  causes  their  lining  membrane  to  contract  in 
a  manner  that  produces  coagulation  and  stops  hemor- 
rhage. It  is  remarkable  that  so  simple  and  practical  a 
method  as  the  use  of  the  ligature  in  stopping  hemor- 
rhage could  have  gone  out  of  use,  once  it  had  been  dis- 
covered; but  during  the  Middle  Ages  it  was  almost 
entirely  lost  sight  of,  and  was  not  reintroduced  until 
the  time  of  Ambroise  Pare,  in  the  sixteenth  century. 

Even  at  a  very  early  period  the  Romans  recognized 
the  advantage  of  surgical  methods  on  the  field  of 
battle.     Each   soldier   was   supplied   with   bandages, 

275 


A   HISTORY   OF  SCIENCE 

and  was  probably  instructed  in  applying  them,  some- 
thing in  the  same  manner  as  is  done  now  in  all 
modern  armies.  The  Romans  also  made  use  of  mili- 
tary hospitals  and  had  established  a  rude  but  very 
practical  field-ambulance  service.  "  In  every  troop  or 
bandon  of  two  or  four  hundred  men,  eight  or  ten  stout 
fellows  were  deputed  to  ride  immediately  behind  the 
fighting-line  to  pick  up  and  rescue  the  wounded,  for 
which  purpose  their  saddles  had  two  stirrups  on  the 
left  side,  while  they  themselves  were  provided  with 
water-flasks,  and  perhaps  applied  temporary  bandages. 
They  were  encouraged  by  a  reward  of  a  piece  of  gold 
for  each  man  they  rescued.  'Noscomi'  were  male 
nurses  attached  to  the  military  hospitals,  but  not  in- 
scribed '  on  strength '  of  the  legions,  and  were  probably 
for  the  most  part  of  the  servile  class."  6 

From  the  time  of  the  early  Alexandrians,  Herophilus 
and  Erasistratus,  whose  work  we  have  already  exam- 
ined, there  had  been  various  anatomists  of  some  im- 
portance in  the  Alexandrian  school,  though  none  quite 
equal  to  these  earlier  workers.  The  best-known  names 
are  those  of  Celsus  (of  whom  we  have  already  spoken) , 
who  continued  the  work  of  anatomical  investigation, 
and  Marinus,  who  lived  during  the  reign  of  Nero,  and 
Rufus  of  Ephesus.  Probably  all  of  these  wTould  have 
been  better  remembered  by  succeeding  generations 
had  their  efforts  not  been  eclipsed  by  those  of  Galen. 
This  greatest  of  ancient  anatomists  was  born  at  Per- 
gamus  of  Greek  parents.  His  father,  Nicon,  was  an 
architect  and  a  man  of  considerable  ability.  Until  his 
fifteenth  year  the  youthful  Galen  was  instructed  at 
home,  chiefly  by  his  father ;  but  after  that  time  he  was 

276 


SCIENCE   OF   THE    ROMAN    PERIOD 

placed  under  suitable  teachers  for  instruction  in  the 
philosophical  systems  in  vogue  at  that  period.  Shortly 
after  this,  however,  the  superstitious  Nicon,  following 
the  interpretations  of  a  dream,  decided  that  his  son 
should  take  up  the  study  of  medicine,  and  placed  him 
under  the  instruction  of  several  learned  physicians. 

Galen  was  a  tireless  worker,  making  long  tours  into 
Asia  Minor  and  Palestine  to  improve  himself  in  phar- 
macology, and  studying  anatomy  for  some  time  at 
Alexandria.  He  appears  to  have  been  full  of  the  super- 
stitions of  the  age,  however,  and  early  in  his  career 
made  an  extended  tour  into  western  Asia  in  search  of 
the  chimerical  "jet-stone" — a  stone  possessing  the 
peculiar  qualities  of  "burning  with  a  bituminous  odor 
and  supposed  to  possess  great  potency  in  curing  such 
diseases  as  epilepsy,  hysteria,  and  gout." 

By  the  time  he  had  reached  his  twenty-eighth  year 
he  had  perfected  his  education  in  medicine  and  re- 
turned to  his  home  in  Pergamus.  Even  at  that  time 
he  had  acquired  considerable  fame  as  a  surgeon,  and 
his  fellow-citizens  showed  their  confidence  in  his  ability 
by  choosing  him  as  surgeon  to  the  wounded  gladiators 
shortly  after  his  return  to  his  native  city.  In  these 
duties  his  knowledge  of  anatomy  aided  him  greatly, 
and  he  is  said  to  have  healed  certain  kinds  of  wounds 
that  had  previously  baffled  the  surgeons. 

In  the  time  of  Galen  dissections  of  the  human  body 
were  forbidden  by  law,  and  he  was  obliged  to  confine 
himself  to  dissections  of  the  lower  animals.  He  had 
the  advantage,  however,  of  the  anatomical  works  of 
Herophilus  and  Erasistratus,  and  he  must  have  de- 
pended upon  them  in  perfecting  his  comparison  between 

?77 


A   HISTORY   OF   SCIENCE 

the  anatomy  of  men  and  the  lower  animals.  It  is 
possible  that  he  did  make  human  dissections  surrep- 
titiously, but  of  this  we  have  no  proof. 

He  was  familiar  with  the  complicated  structure  of 
the  bones  of  the  cranium.  He  described  the  vertebras 
clearly,  divided  them  into  groups,  and  named  them 
after  the  manner  of  anatomists  of  to-day.  He  was  less 
accurate  in  his  description  of  the  muscles,  although  a 
large  number  of  these  were  described  by  him.  Like  all 
anatomists  before  the  time  of  Harvey,  he  had  a  very 
erroneous  conception  of  the  circulation,  although  he 
understood  that  the  heart  was  an  organ  for  the  propul- 
sion of  blood,  and  he  showed  that  the  arteries  of  the  liv- 
ing animals  did  not  contain  air  alone,  as  was  taught  by 
many  anatomists.  He  knew,  also,  that  the  heart  was 
made  up  of  layers  of  fibres  that  ran  in  certain  fixed 
directions-^that  is,  longitudinal,  transverse,  and  ob- 
lique; but[he  did  not  recognize  the  heart  as  a  muscular 
organ.  In  proof  of  this  he  pointed  out  that  all  muscles 
require  rest,  and  as  the  heart  did  not  rest  it  could  not 
be  composed  of  muscular  tissueJ 

Many  of  his  physiological  experiments  were  conduct- 
ed upon  scientific  principles.  Thus  he  proved  that 
certain  muscles  were  under  the  control  of  definite  sets 
of  nerves  by  cutting  these  nerves  in  living  animals,  and 
observing  that  the  muscles  supplied  by  them  were  ren- 
dered useless.  He  pointed  out  also  that  nerves  have 
no  power  in  themselves,  but  merely  conduct  impulses 
to  and  from  the  brain  and  spinal-cord.  He  turned  this 
peculiar  knowledge  to  account  in  the  case  of  a  cele- 
brated sophist,  Pausanias,  who  had  been  under  the 
treatment  of  various  physicians  for  a  numbness  in  the 

278 


SCIENCE   OF   THE   ROMAN   PERIOD 

fourth  and  fifth  fingers  of  his  left  hand.  These  physi- 
cians had  been  treating  this  condition  by  applications 
of  poultices  to  the  hand  itself.  Galen,  being  called  in 
consultation,  pointed  out  that  the  injury  was  prob- 
ably not  in  the  hand  itself,  but  in  the  ulner  nerve,  which 
controls  sensation  in  the  fourth  and  fifth  fingers. 
Surmising  that  the  nerve  must  have  been  injured  in 
some  way,  he  made  careful  inquiries  of  the  patient,  who 
recalled  that  he  had  been  thrown  from  his  chariot 
some  time  before,  striking  and  injuring  his  back.  Act- 
ing upon  this  information,  Galen  applied  stimulating 
remedies  to  the  source  of  the  nerve  itself — that  is,  to 
the  bundle  of  nerve-trunks  known  as  the  brachial 
plexus,  in  the  shoulder.  To  the  surprise  and  con- 
fusion of  his  fellow-physicians,  this  method  of  treat- 
ment proved  effective  and  the  patient  recovered  com- 
pletely in  a  short  time. 

Although  the  functions  of  the  organs  in  the  chest 
were  not  well  understood  by  Galen,  he  was  well  ac- 
quainted with  their  anatomy.  He  knew  that  the  lungs 
were  covered  by  thin  membrane,  and  that  the  heart 
was  surrounded  by  a  sac  of  very  similar  tissue.  He 
made  constant  comparisons  also  between  these  organs 
in  different  animals,  as  his  dissections  were  performed 
upon  beasts  ranging  in  size  from  a  mouse  to  an  elephant. 
The  minuteness  of  his  observations  is  shown  -by  the 
fact  that  he  had  noted  and  described  the  ring  of  bone 
found  in  the  hearts  of  certain  animals,  such  as  the 
horse,  although  not  found  in  the  human  heart  or  in 
most  animals. 

His  description  of  the  abdominal  organs  was  in 
general  accurate.     He  had  noted  that  the  abdominal 

279 


A   HISTORY   OF   SCIENCE 

cavity  was  lined  with  a  peculiar  saclike  membrane,  the 
peritoneum,  which  also  surrounded  most  of  the  organs 
contained  in  the  cavity,  and  he  made  special  note  that 
this  membrane  also  enveloped  the  liver  in  a  peculiar 
manner.  The  exactness  of  the  last  observation  seems 
the  more  wonderful  when  we  reflect  that  even  to-day 
the  medical  student  finds  a  correct  understanding  of 
the  position  of  the  folds  of  the  peritoneum  one  of  the 
most  difficult  subjects  in  anatomy. 

As  a  practical  physician  he  was  held  in  the  highest 
esteem  by  the  Romans.  The  Emperor  Marcus  Aurelius 
called  him  to  Rome  and  appointed  him  physician-in- 
ordinary  to  his  son  Commodus,  and  on  special  occa- 
sions Marcus  Aurelius  himself  called  in  Galen  as  his 
medical  adviser.  On  one  occasion,  the  three  army  sur- 
geons in  attendance  upon  the  emperor  declared  that  he 
was  about  to  be  attacked  by  a  fever.  Galen  relates 
how  "on  special  command  I  felt  his  pulse,  and  finding 
it  quite  normal,  considering  his  age  and  the  time  of 
day,  I  declared  it  was  no  fever  but  a  digestive  dis- 
order, due  to  the  food  he  had  eaten,  which  must  be 
converted  into  phlegm  before  being  excreted.  Then 
the  emperor  repeated  three  times,  'That's  the  very 
thing,'  and  asked  what  was  to  be  done.  I  answered 
that  I  usually  gave  a  glass  of  wine  with  pepper  sprin- 
kled on  it,  but  for  you  kings  we  only  use  the  safest 
remedies,  and  it  will  suffice  to  apply  wool  soaked  in 
hot  nard  ointment  locally.  The  emperor  ordered  the 
wool,  wine,  etc.,  to  be  brought,  and  I  left  the  room. 
His  feet  were  warmed  by  rubbing  with  hot  hands,  and 
after  drinking  the  peppered  wine,  he  said  to  Pitholaus 
(his  son's  tutor),  'We  have  only  one  doctor,  and  that 

280 


c? 


Galierv  natif-  de  J?ergarn.e.  villa  duAsiet  cxcetUntiMecUciw 
■vuLOit  au  temps  aes  Ernpereurs  cAntomnle^hiloJo 
etde  Commoauj f  orthent  qti'ii  a,  vescu  ia.0  ahs. 


firhT) 


GALEN 
(From  an  old  print.) 


SCIENCE   OF   THE   ROMAN    PERIOD 

an  honest  one,'  and  went  on  to  describe  me  as  the  first 
of  physicians  and  the  only  philosopher,  for  he  had 
tried  many  before  who  were  not  only  lovers  of  money, 
but  also  contentious,  ambitious,  envious,  and  malig- 
nant." 7 

It  will  be  seen  from  this  that  Galen  had  a  full  appre- 
ciation of  his  own  abilities  as  a  physician,  but  inas- 
much as  succeeding  generations  for  a  thousand  years 
concurred  in  the  alleged  statement  made  by  Marcus 
Aurelius  as  to  his  ability,  he  is  perhaps  excusable  for 
his  open  avowal  of  his  belief  in  his  powers.  His  faith 
in  his  accuracy  in  diagnosis  and  prognosis  was  shown 
when  a  colleague  once  said  to  him,  "I  have  used  the 
prognostics  of  Hippocrates  as  well  as  you.  Why  can 
I  not  prognosticate  as  well  as  you?"  To  this  Galen 
replied,  "  By  God's  help  I  have  never  been  deceived  in 
my  prognosis."  8  It  is  probable  that  this  statement 
was  made  in  the  heat  of  argument,  and  it  is  hardly  to 
be  supposed  that  he  meant  it  literally. 

His  systems  of  treatment  were  far  in  advance  of  his 
theories  regarding  the  functions  of  organs,  causes  of 
disease,  etc.,  and  some  of  them  are  still  first  principles 
with  physicians.  Like  Hippocrates,  he  laid  great  stress 
on  correct  diet,  exercise,  and  reliance  upon  nature. 
"  Nature  is  the  overseer  by  whom  health  is  supplied 
to  the  sick,"  he  says.  "Nature  lends  her  aid  on  all 
sides,  she  decides  and  cures  diseases.  No  one  can  be 
saved  unless  nature  conquers  the  disease,  and  no  one 
dies  unless  nature  succumbs." 

From  the  picture  thus  drawn  of  Galen  as  an  anato- 
mist and  physician,  one  might  infer  that  he  should  rank 
very  high  as  a  scientific  exponent  of  medicine,  even  in 

281 


A   HISTORY   OF   SCIENCE 

comparison  with  modern  physicians.  There  is,  how- 
ever, another  side  to  the  picture.  His  knowledge  of 
anatomy  was  certainly  very  considerable,  but  many  of 
his  deductions  and  theories  as  to  the  functions  of  or- 
gans, the  cause  of  diseases,  and  his  methods  of  treating 
them,  would  be  recognized  as  absurd  by  a  modern 
school-boy  of  average  intelligence.  His  greatness  must 
be  judged  in  comparison  with  ancient,  not  with  mod- 
ern, scientists.  He  maintained,  for  example,  that 
respiration  and  the  pulse-beat  were  for  one  and  the 
same  purpose — that  of  the  reception  of  air  into  the 
arteries  of  the  body.  To  him  the  act  of  breathing 
was  for  the  purpose  of  admitting  air  into  the  lungs, 
whence  it  found  its  way  into  the  heart,  and  from  there 
was  distributed  throughout  the  body  by  means  of  the 
arteries.  The  skin  also  played  an  important  part  in 
supplying  the  body  with  air,  the  pores  absorbing  the 
air  and  distributing  it  through  the  arteries.  But,  as  we 
know  that  he  was  aware  of  the  fact  that  the  arteries 
also  contained  blood,  he  must  have  believed  that  these 
vessels  contained  a  mixture  of  the  two. 

Modern  anatomists  know  that  the  heart  is  divided 
into  two  approximately  equal  parts  by  an  impermeable 
septum  of  tough  fibres.  Yet,  Galen,  who  dissected 
the  hearts  of  a  vast  number  of  the  lower  animals  ac- 
cording to  his  own  account,  maintained  that  this  sep- 
tum was  permeable,  and  that  the  air,  entering  one  side 
of  the  heart  from  the  lungs,  passed  through  it  into 
the  opposite  side  and  was  then  transferred  to  the 
arteries. 

He  was  equally  at  fault,  although  perhaps  more 
excusably  so,  in  his  explanation  of  the  action  of  the 

282 


SCIENCE   OF   THE   ROMAN    PERIOD 

nerves.  He  had  rightly  pointed  out  that  nerves  were 
merely  connections  between  the  brain  and  spinal-cord 
and  distant  muscles  and  organs,  and  had  recognized 
that  there  were  two  kinds  of  nerves,  but  his  explana- 
tion of  the  action  of  these  nerves  was  that  "nervous 
spirits"  were  carried  to  the  cavities  of  the  brain  by 
blood-vessels,  and  from  there  transmitted  through  the 
body  along  the  nerve- trunks. 

In  the  human  skull,  overlying  the  nasal  cavity,  there 
are  two  thin  plates  of  bone  perforated  with  numerous 
small  apertures.  These  apertures  allow  the  passage 
of  numerous  nerve-filaments  which  extend  from  a  group 
of  cells  in  the  brain  to  the  delicate  membranes  in  the 
nasal  cavity.  These  perforations  in  the  bone,  there- 
fore, are  simply  to  allow  the  passage  of  the  nerves. 
But  Galen  gave  a  very  different  explanation.  He  be- 
lieved that  impure  "animal  spirits"  were  carried  to 
the  cavities  of  the  brain  by  the  arteries  in  the  neck 
and  from  there  were  sifted  out  through  these  perforated 
bones,  and  so  expelled  from  the  body. 

He  had  observed  that  the  skin  played  an  important 
part  in  cooling  the  body,  but  he  seems  to  have  be- 
lieved that  the  heart  was  equally  active  in  overheating 
it.  The  skin,  therefore,  absorbed  air  for  the  purpose 
of  "cooling  the  heart,"  and  this  cooling  process  was 
aided  by  the  brain,  whose  secretions  aided  also  in  the 
cooling  process.  The  heart  itself  was  the  seat  of  cour- 
age ;  the  brain  the  seat  of  the  rational  soul ;  and  the  liver 
the  seat  of  love. 

The  greatness  of  Galen's  teachings  lay  in  his  knowl- 
edge of  anatomy  of  the  organs ;  his  weakness  was  in  his 
interpretations  of  their  functions.     Unfortunately,  suc- 

283 


A   HISTORY   OF   SCIENCE 

ceeding  generations  of  physicians  for  something  like  a 
thousand  years  rejected  the  former  but  clung  to  the 
latter,  so  that  the  advances  he  had  made  were  com- 
pletely overshadowed  by  the  mistakes  of  his  teachings. 


X 

A   RETROSPECTIVE   GLANCE   AT  CLASSICAL 
SCIENCE 

IT  is  a  favorite  tenet  of  the  modern  historian  that 
history  is  a  continuous  stream.  The  contention 
has  fullest  warrant.  Sharp  lines  of  demarcation  are 
an  evidence  of  man's  analytical  propensity  rather 
than  the  work  of  nature.  Nevertheless  it  would  be 
absurd  to  deny  that  the  stream  of  history  presents 
an  ever- varying  current.  There  are  times  when  it 
seems  to  rush  rapidly  on;  times  when  it  spreads  out 
into  a  broad — seemingly  static — current;  times  when 
its  catastrophic  changes  remind  us  of  nothing  but  a 
gigantic  cataract.  Rapids  and  whirlpools,  broad  est- 
uaries and  tumultuous  cataracts  are  indeed  part  of 
the  same  stream,  but  they  are  parts  that  vary  one 
from  another  in  their  salient  features  in  such  a  way  as 
to  force  the  mind  to  classify  them  as  things  apart  and 
give  them  individual  names. 

So  it  is  with  the  stream  of  history ;  however  strongly 
we  insist  on  its  continuity  we  are  none  the  less  forced 
to  recognize  its  periodicity.  It  may  not  be  desirable 
to  fix  on  specific  dates  as  turning-points  to  the  extent 
that  our  predecessors  were  wont  to  do.  We  may  not, 
for  example,  be  disposed  to  admit  that  the  Roman 
Empire  came  to  any  such  cataclysmic  finish  as  the 
year  476  a.d.,  when  cited  in  connection  with  the  over- 

285 


•     A   HISTORY    OF    SCIENCE 

throw  of  the  last  Roman  Empire  of  the  West,  might 
seem  to  indicate.  But,  on  the  other  hand,  no  student 
of  the  period  can  fail  to  realize  that  a  great  change 
came  over  the  aspect  of  the  historical  stream  towards 
the  close  of  the  Roman  epoch. 

The  span  from  Thales  to  Galen  has  compassed  about 
eight  hundred  years  —  let  us  say  thirty  generations. 
Throughout  this  period  there  is  scarcely  a  generation 
that  has  not  produced  great  scientific  thinkers — men 
who  have  put  their  mark  upon  the  progress  of  civiliza- 
tion; but  we  shall  see,  as  we  look  forward  for  a  cor- 
responding period,  that  the  ensuing  thirty  generations 
produced  scarcely  a  single  scientific  thinker  of  the 
first  rank.  Eight  hundred  years  of  intellectual  ac- 
tivity—  thirty  generations  of  greatness;  then  eight 
hundred  years  of  stasis — thirty  generations  of  medioc- 
rity; such  seems  to  be  the  record  as  viewed  in  per- 
spective. Doubtless  it  seemed  far  different  to  the 
contemporary  observer;  it  is  only  in  reasonable  per- 
spective that  any  scene  can  be  viewed  fairly.  But  for 
us,  looking  back  without  prejudice  across  the  stage  of 
years,  it  seems  indisputable  that  a  great  epoch  came 
to  a  close  at  about  the  time  when  the  barbarian 
nations  of  Europe  began  to  sweep  down  into  Greece 
and  Italy.  We  are  forced  to  feel  that  we  have  reached 
the  limits  of  progress  of  what  historians  are  pleased  to 
call  the  ancient  world.  For  about  eight  hundred  years 
Greek  thought  has  been  dominant,  but  in  the  ensuing 
period  it  is  to  play  a  quite  subordinate  part,  except 
in  so  far  as  it  influences  the  thought  of  an  alien  race. 
As  we  leave  this  classical  epoch,  then,  we  may  well 
recapitulate  in  brief  its  triumphs.     A  few  words  will 

286 


A   RETROSPECTIVE   GLANCE 

suffice  to  summarize  a  story  the  details  of  which  have 
made  up  our  recent  chapters. 

In  the  field  of  cosmology,  Greek  genius  has  demon- 
strated that  the  earth  is  spheroidal,  that  the  moon  is 
earthlike  in  structure  and  much  smaller  than  our 
globe,  and  that  the  sun  is  vastly  larger  and  many 
times  more  distant  than  the  moon.  The  actual  size  of 
the  earth  and  the  angle  of  its  axis  with  the  ecliptic 
have  been  measured  with  approximate  accuracy.  It 
has  been  shown  that  the  sun  and  moon  present  in- 
equalities of  motion  which  may  be  theoretically  ex- 
plained by  supposing  that  the  earth  is  not  situated 
precisely  at  the  centre  of  their  orbits.  A  system  of 
eccentrics  and  epicycles  has  been  elaborated  which 
serves  to  explain  the  apparent  motions  of  the  heavenly 
bodies  in  a  manner  that  may  be  called  scientific  even 
though  it  is  based,  as  we  now  know,  upon  a  false 
hypothesis.  The  true  hypothesis,  which  places  the 
sun  at  the  centre  of  the  planetary  system  and  postu- 
lates the  orbital  and  axial  motions  of  our  earth  in 
explanation  of  the  motions  of  the  heavenly  bodies,  has 
been  put  forward  and  ardently  championed,  but,  un- 
fortunately, is  not  accepted  by  the  dominant  thinkers 
at  the  close  of  our  epoch.  In  this  regard,  therefore,  a 
vast  revolutionary  work  remains  for  the  thinkers  of  a 
later  period.  Moreover,  such  observations  as  the 
precession  of  the  equinoxes  and  the  moon's  evection 
are  as  yet  unexplained,  and  measurements  of  the 
earth's  size,  and  of  the  sun's  size  and  distance,  are  so 
crude  and  imperfect  as  to  be  in  one  case  only  an  ap- 
proximation, and  in  the  other  an  absurdly  inadequate 
suggestion.     But   with   all   these   defects,    the    total 

287 


A   HISTORY   OF   SCIENCE 

achievement  of  the  Greek  astronomers  is  stupendous. 
To  have  clearly  grasped  the  idea  that  the  earth  is 
round  is  in  itself  an  achievement  that  marks  off  the 
classical  from  the  Oriental  period  as  by  a  great  gulf. 

In  the  physical  sciences  we  have  seen  at  least  the 
beginnings  of  great  things.  Dynamics  and  hydro- 
statics may  now,  for  the  first  time,  claim  a  place 
among  the  sciences.  Geometry  has  been  perfected  and 
trigonometry  has  made  a  sure  beginning.  The  con- 
ception that  there  are  four  elementary  substances, 
earth,  water,  air,  and  fire,  may  not  appear  a  secure 
foundation  for  chemistry,  yet  it  marks  at  least  an 
attempt  in  the  right  direction.  Similarly,  the  concep- 
tion that  all  matter  is  made  up  of  indivisible  particles 
and  that  these  have  adjusted  themselves  and  are 
perhaps  held  in  place  by  a  whirling  motion,  while  it  is 
scarcely  more  than  a  scientific  dream,  is,  after  all,  a 
dream  of  marvellous  insight. 

In  the  field  of  biological  science  progress  has  not 
been  so  marked,  yet  the  elaborate  garnering  of  facts 
regarding  anatomy,  physiology,  and  the  zoological 
sciences  is  at  least  a  valuable  preparation  for  the 
generalizations  of  a  later  time. 

If  with  a  map  before  us  we  glance  at  the  portion  of 
the  globe  which  was  known  to  the  workers  of  the 
period  now  in  question,  bearing  in  mind  at  the  same 
time  what  we  have  learned  as  to  the  seat  of  labors  of 
the  various  great  scientific  thinkers  from  Thales  to 
Galen,  we  cannot  fail  to  be  struck  with  a  rather  star- 
tling fact,  intimations  of  which  have  been  given  from 
time  to  time  —  the  fact,  namely,  that  most  of  the 
great  Greek  thinkers  did  not  live  in  Greece  itself.     As 


A   RETROSPECTIVE   GLANCE 

our  eye  falls  upon  Asia  Minor  and  its  outlying  islands, 
we  reflect  that  here  were  born  such  men  as  Thales, 
Anaximander,  Anaximenes,  Heraclitus,  Pythagoras, 
Anaxagoras,  Socrates,  Aristarchus,  Hipparchus,  Eu- 
doxus,  Philolaus,  and  Galen.  From  the  northern 
shores  of  the  ^Egean  came  Lucippus,  Democritus,  and 
Aristotle.  Italy,  off  to  the  west,  is  the  home  of 
Pythagoras  and  Xenophanes  in  their  later  years,  and 
of  Parmenides  and  Empedocles,  Zeno,  and  Archimedes. 
Northern  Africa  can  claim,  by  birth  or  by  adoption, 
such  names  as  Euclid,  Apollonius  of  Perga,  Heroph- 
ilus,  Erasistratus,  Aristippus,  Eratosthenes,  Ctesibius, 
Hero,  Strabo,  and  Ptolemy.  This  is  but  running  over 
the  list  of  great  men  whose  discoveries  have  claimed 
our  attention.  Were  we  to  extend  the  list  to  include 
a  host  of  workers  of  the  second  rank,  we  should  but 
emphasize  the  same  fact. 

All  along  we  are  speaking  of  Greeks,  or,  as  they  call 
themselves,  Hellenes,  and  we  mean  by  these  words  the 
people  whose  home  was  a  small  jagged  peninsula 
jutting  into  the  Mediterranean  at  the  southeastern 
extremity  of  Europe.  We  think  of  this  peninsula 
as  the  home  of  Greek  culture,  yet  of  all  the  great 
thinkers  we  have  just  named,  not  one  was  born  on 
this  peninsula,  and  perhaps  not  one  in  five  ever  set 
foot  upon  it.  In  point  of  fact,  one  Greek  thinker  of  the 
very  first  rank,  and  one  only,  was  born  in  Greece 
proper;  that  one,  however,  was  Plato,  perhaps  the 
greatest  of  them  all.  With  this  one  brilliant  exception 
(and  even  he  was  born  of  parents  who  came  from 
the  provinces),  all  the  great  thinkers  of  Greece  had 
their  origin  at  the  circumference  rather  than  the  centre 

VOL.  I.— 19  289 


A   HISTORY   OF   SCIENCE 

of  the  empire.  And  if  we  reflect  that  this  circum- 
ference of  the  Greek  world  was  in  the  nature  of  the  case 
the  widely  circling  region  in  which  the  Greek  came  in 
contact  with  other  nations,  we  shall  see  at  once  that 
there  could  be  no  more  striking  illustration  in  all 
history  than  that  furnished  us  here  of  the  value  of 
racial  mingling  as  a  stimulus  to  intellectual  progress. 
But  there  is  one  other  feature  of  the  matter  that 
must  not  be  overlooked.  Racial  mingling  gives 
vitality,  but  to  produce  the  best  effect  the  mingling 
must  be  that  of  races  all  of  which  are  at  a  relatively 
high  plane  of  civilization.  In  Asia  Minor  the  Greek 
mingled  with  the  Semite,  who  had  the  heritage  of 
centuries  of  culture;  and  in  Italy  with  the  Umbrians, 
Oscans,  and  Etruscans,  who,  little  as  we  know  of  their 
antecedents,  have  left  us  monuments  to  testify  to  their 
high  development.  The  chief  reason  why  the  racial 
mingling  of  a  later  day  did  not  avail  at  once  to  give  new 
life  to  Roman  thought  was  that  the  races  which  swept 
down  from  the  north  were  barbarians.  It  was  no  more 
possible  that  they  should  spring  to  the  heights  of 
classical  culture  than  it  would,  for  example,  be  possible 
in  two  or  three  generations  to  produce  a  racer  from 
a  stock  of  draught  horses.  Evolution  does  not  proceed 
by  such  vaults  as  this  would  imply.  Celt,  Goth, 
Hun,  and  Slav  must  undergo  progressive  development 
for  many  generations  before  the  population  of  north- 
ern Europe  can  catch  step  with  the  classical  Greek  and 
prepare  to  march  forward.  That,  perhaps,  is  one 
reason  why  we  come  to  a  period  of  stasis  or  retro- 
gression when  the  time  of  classical  activity  is  over. 
But,  at  best,  it  is  only  one  reason  of  several. 

290 


A   RETROSPECTIVE   GLANCE 

The  influence  of  the  barbarian  nations  will  claim 
further  attention  as  we  proceed.  But  now,  for  the 
moment,  we  must  turn  our  eyes  in  the  other  direction 
and  give  attention  to  certain  phases  of  Greek  and  of 
Oriental  thought  which  were  destined  to  play  a  most 
important  part  in  the  development  of  the  Western 
mind — a  more  important  part,  indeed,  in  the  early 
mediaeval  period  than  that  played  by  those  important 
inductions  of  science  which  have  chiefly  claimed  our 
attention  in  recent  chapters.  The  subject  in  question 
is  the  old  familiar  one  of  false  inductions  or  .pseudo- 
science.  In  dealing  with  the  early  development  of 
thought  and  with  Oriental  science,  we  had  occasion 
to  emphasize  the  fact  that  such  false  inductions  led 
everywhere  to  the  prevalence  of  superstition.  In 
dealing  with  Greek  science,  we  have  largely  ignored 
this  subject,  confining  attention  chiefly  to  the  pro- 
gressive phases  of  thought;  but  it  must  not  be  in- 
ferred from  this  that  Greek  science,  with  all  its  secure 
inductions,  was  entirely  free  from  superstition.  On 
the  contrary,  the  most  casual  acquaintance  with  Greek 
literature  would  suffice  to  show  the  incorrectness  of 
such  a  supposition.  True,  the  great  thinkers  of  Greece 
were  probably  freer  from  this  thraldom  of  false  in- 
ductions than  any  of  their  predecessors.  Even  at  a 
very  early  day  such  men  as  Xenophanes,  Empedocles, 
Anaxagoras,  and  Plato  attained  to  a  singularly  ration- 
alistic conception  of  the  universe. 

We  saw  that  "  the  father  of  medicine,"  Hippocrates, 
banished  demonology  and  conceived  disease  as  due  to 
natural  causes.  At  a  slightly  later  day  the  sophists 
challenged  all  knowledge,  and  Pyrrhonism  became  a 

291 


A    HISTORY   OF  SCIENCE 

synonym  for  scepticism  in  recognition  of  the  leader- 
ship of  a  master  doubter.  The  entire  school  of 
Alexandrians  must  have  been  relatively  free  from 
superstition,  else  they  could  not  have  reasoned  with 
such  effective  logicality  from  their  observations  of 
nature.  It  is  almost  inconceivable  that  men  like 
Euclid  and  Archimedes,  and  Aristarchus  and  Era- 
tosthenes, and  Hipparchus  and  Hero,  could  have  been 
the  victims  of  such  illusions  regarding  occult  forces 
of  nature  as  were  constantly  postulated  by  Orien- 
tal science.  Herophilus  and  Erasistratus  and  Galen 
would  hardly  have  pursued  their  anatomical  studies 
with  equanimity  had  they  believed  that  ghostly  ap- 
paritions watched  over  living  and  dead  alike,  and 
exercised  at  will  a  malign  influence. 

Doubtless  the  Egyptian  of  the  period  considered 
the  work  of  the  Ptolemaic  anatomists  an  unspeakable 
profanation,  and,  indeed,  it  was  nothing  less  than  rev- 
olutionary —  so  revolutionary  that  it  could  not  be 
sustained  in  subsequent  generations.  We  have  seen 
that  the  great  Galen,  at  Rome,  five  centuries  after 
the  time  of  Herophilus,  was  prohibited  from  dissecting 
the  human  subject.  The  fact  speaks  volumes  for  the 
attitude  of  the  Roman  mind  towards  science.  Vast 
audiences  made  up  of  every  stratum  of  society  thronged 
the  amphitheatre,  and  watched  exultingly  while  man 
slew  his  fellow-man  in  single  or  in  multiple  combat. 
Shouts  of  frenzied  joy  burst  from  a  hundred  thou- 
sand throats  when  the  death-stroke  was  given  to  a  new 
victim.  The  bodies  of  the  slain,  by  scores,  even  by 
hundreds,  were  dragged  ruthlessly  from  the  arena  and 
hurled  into  a  ditch  as  contemptuously  as  if  pity  were 

292 


A   RETROSPECTIVE    GLANCE 

yet  unborn  and  human  life  the  merest  bauble.  Yet 
the  same  eyes  that  witnessed  these  scenes  with  ecstat- 
ic approval  would  have  been  averted  in  pious  horror 
had  an  anatomist  dared  to  approach  one  of  the  muti- 
lated bodies  with  the  scalpel  of  science.  It  was  sport 
to  see  the  blade  of  the  gladiator  enter  the  quivering, 
living  flesh  of  his  fellow-gladiator;  it  was  joy  to  see  the 
warm  blood  spurt  forth  from  the  writhing  victim 
while  he  still  lived;  but  it  were  sacrilegious  to  ap- 
proach that  body  with  the  knife  of  the  anatomist, 
once  it  had  ceased  to  pulsate  with  life.  Life  itself  was 
held  utterly  in  contempt,  but  about  the  realm  of  death 
hovered  the  threatening  ghosts  of  superstition.  And 
such,  be  it  understood,  was  the  attitude  of  the  Roman 
populace  in  the  early  and  the  most  brilliant  epoch 
of  the  empire,  before  the  Western  world  came  under 
the  influence  of  that  Oriental  philosophy  which  was 
presently  to  encompass  it. 

In  this  regard  the  Alexandrian  world  was,  as  just 
intimated,  far  more  advanced  than  the  Roman,  yet 
even  there  we  must  suppose  that  the  leaders  of  thought 
were  widely  at  variance  with  the  popular  conceptions. 
A  few  illustrations,  drawn  from  Greek  literature  at 
various  ages,  will  suggest  the  popular  attitude.  In 
the  first  instance,  consider  the  poems  of  Homer  and  of 
Hesiod.  For  these  writers,  and  doubtless  for  the 
vast  majority  of  their  readers,  not  merely  of  their  own 
but  of  many  subsequent  generations,  the  world  is 
peopled  with  a  multitude  of  invisible  apparitions, 
which,  under  title  of  gods,  are  held  to  dominate  the 
affairs  of  man.  It  is  sometimes  difficult  to  dis- 
criminate as  to  where  the  Greek  imagination  drew 

293 


A   HISTORY   OF   SCIENCE 

the  line  between  fact  and  allegory;  nor  need  we  at- 
tempt to  analyse  the  early  poetic  narratives  to  this  end. 
It  will  better  serve  our  present  purpose  to  cite  three 
or  four  instances  which  illustrate  the  tangibility  of 
beliefs  based  upon  pseudo-scientific  inductions. 

Let  us  cite,  for  example,  the  account  which  Herodo- 
tus gives  us  of  the  actions  of  the  Greeks  at  Platsea,  when 
their  army  confronted  the  remnant  of  the  army  of 
Xerxes,  in  the  year  479  b.c.  Here  we  see  each  side 
hesitating  to  attack  the  other,  merely  because  the 
oracle  had  declared  that  whichever  side  struck  the  first 
blow  would  lose  the  conflict.  Even  after  the  Persian 
soldiers,  who  seemingly  were  a  jot  less  superstitious  or 
a  shade  more  impatient  than  their  opponents,  had 
begun  the  attack,  we  are  told  that  the  Greeks  dared 
not  respond  at  first,  though  they  were  falling  before 
the  javelins  of  the  enemy,  because,  forsooth,  the  en- 
trails of  a  fowl  did  not  present  an  auspicious  ap- 
pearance. And  these  were  Greeks  of  the  same  genera- 
tion with  Empedocles  and  Anaxagoras  and  ^schylus ; 
of  the  same  epoch  with  Pericles  and  Sophocles  and 
Euripides  and  Phidias.  Such  wTas  the  scientific  status 
of  the  average  mind — nay,  of  the  best  minds — with 
here  and  there  a  rare  exception,  in  the  golden  age  of 
Grecian  culture. 

Were  we  to  follow  down  the  pages  of  Greek  history, 
we  should  but  repeat  the  same  story  over  and  over. 
We  should,  for  example,  see  Alexander  the  Great  balked 
at  the  banks  of  the  Hyphasis,  and  forced  to  turn  back 
because  of  inauspicious  auguries  based  as  before  upon 
the  dissection  of  a  fowl.  Alexander  himself,  to  be  sure, 
would  have  scorned  the  augury ;  had  he  been  the  prey 

294 


A    RETROSPECTIVE    GLANCE 

of  such  petty  superstitions  he  would  never  have  con- 
quered Asia.  We  know  how  he  compelled  the  oracle 
at  Delphi  to  yield  to  his  wishes ;  how  he  cut  the  Gordian 
knot;  how  he  made  his  dominating  personality  felt 
at  the  temple  of  Ammon  in  Egypt.  We  know,  in  a 
word,  that  he  yielded  to  superstitions  only  in  so  far  as 
they  served  his  purpose.  Left  to  his  own  devices,  he 
would  not  have  consulted  an  oracle  at  the  banks  of  the 
Hyphasis;  or,  consulting,  would  have  forced  from  the 
oracle  a  favorable  answer.  But  his  subordinates  were 
mutinous  and  he  had  no  choice.  Suffice  it  for  our 
present  purpose  that  the  oracle  was  consulted,  and 
that  its  answer  turned  the  conqueror  back. 

One  or  two  instances  from  Roman  history  may  com- 
plete the  picture.  Passing  over  all  those  mythical 
narratives  which  virtually  constitute  the  early  history 
of  Rome,  as  preserved  to  us  by  such  historians  as 
Livy  and  Dionysius,  we  find  so  logical  an  historian  as 
Tacitus  recording  a  miraculous  achievement  of  Ves- 
pasian without  adverse  comment.  "During  the 
months  when  Vespasian  was  waiting  at  Alexandria  for 
the  periodical  season  of  the  summer  winds,  and  a 
safe  navigation,  many  miracles  occurred  by  which  the 
favor  of  Heaven  and  a  sort  of  bias  in  the  powers  above 
towards  Vespasian  were  manifested."  Tacitus  then 
describes  in  detail  the  cure  of  various  maladies  by  the 
emperor,  and  relates  that  the  emperor  on  visiting  a 
temple  was  met  there,  in  the  spirit,  by  a  prominent 
Egyptian  who  was  proved  to  be  at  the  same  time  some 
eighty  miles  distant  from  Alexandria. 

It  must  be  admitted  that  Tacitus,  in  relating  that 
Vespasian  caused  the  blind  to  see  and  the  lame  to  walk, 

295 


A   HISTORY   OF   SCIENCE 

qualifies  his  narrative  by  asserting  that  "  persons  who 
are  present  attest  the  truth  of  the  transaction  when 
there  is  nothing  to  be  gained  by  falsehood."  Nor 
must  we  overlook  the  fact  that  a  similar  belief  in  the 
power  of  royalty  has  persisted  almost  to  our  own 
day.  But  no  such  savor  of  scepticism  attaches  to  a 
narrative  which  Dion  Cassius  gives  us  of  an  incident 
in  the  life  of  Marcus  Aurelius — an  incident  that  has 
become  famous  as  the  episode  of  The  Thundering 
Legion.  Xiphilinus  has  preserved  the  account  of 
Dion,  adding  certain  picturesque  interpretations  of 
his  own.  The  original  narrative,  as  cited,  asserts  that 
during  one  of  the  northern  campaigns  of  Marcus 
Aurelius,  the  emperor  and  his  army  were  surrounded 
by  the  hostile  Quadi,  who  had  every  advantage  of 
position  and  who  presently  ceased  hostilities  in  the 
hope  that  heat  and  thirst  would  deliver  their  ad- 
versaries into  their  hands  without  the  trouble  of 
further  fighting.  "Now,"  says  Dion,  "while  the 
Romans,  unable  either  to  combat  or  to  retreat,  and 
reduced  to  the  last  extremity  by  wounds,  fatigue,  heat, 
and  thirst,  were  standing  helplessly  at  their  posts, 
clouds  suddenly  gathered  in  great  number  and  rain 
descended  in  floods — certainly  not  without  divine  in- 
tervention, since  the  Egyptian  Maege  Arnulphis,  who 
was  with  Marcus  Antoninus,  is  said  to  have  invoked 
several  genii  by  the  aerial  mercury  by  enchantment, 
and  thus  through  them  had  brought  down  rain." 

Here,  it  will  be  observed,  a  supernatural  explanation 
is  given  of  a  natural  phenomenon.  But  the  narrator 
does  not  stop  with  this.  If  we  are  to  accept  the 
account    of    Xiphilinus,    Dion    brings    forward    some 

296 


A   RETROSPECTIVE   GLANCE 

striking  proofs  of  divine  interference.  Xiphilinus 
gives  these  proofs  in  the  following  remarkable  para- 
graph : 

"Dion  adds  that  when  the  rain  began  to  fall  every 
soldier  lifted  his  head  towards  heaven  to  receive  the 
water  in  his  mouth;  but  afterwards  others  held  out 
their  shields  or  their  helmets  to  catch  the  water  for 
themselves  and  for  their  horses.  Being  set  upon  by 
the  barbarians  .  .  .  while  occupied  in  drinking,  they 
would  have  been  seriously  incommoded  had  not  heavy 
hail  and  numerous  thunderbolts  thrown  consterna- 
tion into  the  ranks  of  the  enemy.  Fire  and  water 
were  seen  to  mingle  as  the}'-  left  the  heavens.  The 
fire,  however,  did  not  reach  the  Romans,  but  if  it  did 
by  chance  touch  one  of  them  it  was  immediately  ex- 
tinguished, while  at  the  same  time  the  rain,  instead 
of  comforting  the  barbarians,  seemed  merely  to  excite 
like  oil  the  fire  with  which  they  were  being  consumed. 
Some  barbarians  inflicted  wounds  upon  themselves  as 
though  their  blood  had  power  to  extinguish  flames, 
while  many  rushed  over  to  the  side  of  the  Romans, 
hoping  that  there  water  might  save  them." 

We  cannot  better  complete  these  illustrations  of 
pagan  credulity  than  by  adding  the  comment  of 
Xiphilinus  himself.  That  writer  was  a  Christian, 
living  some  generations  later  than  Dion.  He  never 
thought  of  questioning  the  facts,  but  he  felt  that 
Dion's  interpretation  of  these  facts  must  not  go  un- 
challenged. As  he  interprets  the  matter,  it  was  no 
pagan  magician  that  wrought  the  miracle.  He  even 
inclines  to  the  belief  that  Dion  himself  was  aware 
that  Christian  interference,  andnot  that  of  an  Egyptian, 

297 


A    HISTORY    OF    SCIENCE 

saved  the  day.  "  Dion  knew,"  he  declares,  "that  there 
existed  a  legion  called  The  Thundering  Legion,  which 
name  was  given  it  for  no  other  reason  than  for  what 
came  to  pass  in  this  war,"  and  that  this  legion  was 
composed  of  soldiers  from  Militene  who  were  all 
professed  Christians.  "During  the  battle,"  continues 
Xiphilinus,  "the  chief  of  the  Pretonians  had  set  at 
Marcus  Antoninus,  who  was  in  great  perplexity  at 
the  turn  events  were  taking,  representing  to  him 
that  there  was  nothing  the  people  called  Christians 
could  not  obtain  by  their  prayers,  and  that  among 
his  forces  was  a  troop  composed  wholly  of  followers  of 
that  religion.  Rejoiced  at  this  news,  Marcus  An- 
toninus demanded  of  these  soldiers  that  they  should 
pray  to  their  god,  who  granted  their  petition  on  the 
instant,  sent  lightning  among  the  enemy  and  con- 
soled the  Romans  with  rain.  Struck  by  this  won- 
derful success,  the  emperor  honored  the  Christians  in 
an  edict  and  named  their  legion  The  Thundering. 
It  is  even  asserted  that  a  letter  existed  by  Marcus 
Antoninus  on  this  subject.  The  pagans  well  knew 
that  the  company  was  called  The  Thunderers,  having 
attested  the  fact  themselves,  but  they  revealed  nothing 
of  the  occasion  on  which  the  leader  received  the 
name."1 

Peculiar  interest  attaches  to  this  narrative  as  illus- 
trating both  credulousness  as  to  matters  of  fact  and 
pseudo-scientific  explanation  of  alleged  facts.  The 
modern  interpreter  may  suppose  that  a  violent  thunder- 
storm came  up  during  the  course  of  a  battle  between 
the  Romans  and  the  so-called  barbarians,  and  that 
owing  to  the  local  character  of  the  storm,  or  a  chance 

298 


A    RETROSPECTIVE    GLANCE 

discharge  of  lightning,  the  barbarians  suffered  more 
than  their  opponents.  We  may  well  question  whether 
the  philosophical  emperor  himself  put  any  other  inter- 
pretation than  this  upon  the  incident.  But,  on  the 
other  hand,  we  need  not  doubt  that  the  major  part  of 
his  soldiers  would  very  readily  accept  such  an  ex- 
planation as  that  given  by  Dion  Cassius,  just  as  most 
readers  of  a  few  centuries  later  would  accept  the  ex- 
planation of  Xiphilinus.  It  is  well  to  bear  this  thought 
in  mind  in  considering  the  static  period  of  science  upon 
which  we  are  entering.  We  shall  perhaps  best  under- 
stand this  period,  and  its  seeming  retrogressions,  if  we 
suppose  that  the  average  man  of  the  Middle  Ages  was 
no  more  credulous,  no  more  superstitious,  than  the 
average  Roman  of  an  earlier  period  or  than  the 
average  Greek;  though  the  precise  complexion  of  his 
credulity  had  changed  under  the  influence  of  Oriental 
ideas,  as  we  have  just  seen  illustrated  by  the  narrative 
of  Xiphilinus. 


APPENDIX 


REFERENCE-LIST,  NOTES,  AND   BIBLIOGRAPHIES 

CHAPTER  I 

PREHISTORIC    SCIENCE 

Length  of  the  Prehistoric  Period. — It  is  of  course  quite  im- 
possible to  reduce  the  prehistoric  period  to  any  definite 
number  of  years.  There  are,  however,  numerous  bits  of 
evidence  that  enable  an  anthropologist  to  make  rough  esti- 
mates as  to  the  relative  lengths  of  the  different  periods  into 
which  prehistoric  time  is  divided.  Gabriel  de  Mortillet,  one 
of  the  most  industrious  students  of  prehistoric  archaeology, 
ventured  to  give  a  tentative  estimate  as  to  the  numbers  of 
years  involved  in  each  period.  He  of  course  claimed  for  this 
nothing  more  than  the  value  of  a  scientific  guess.  It  is,  how- 
ever, a  guess  based  on  a  very  careful  study  of  all  data  at  pres- 
ent available.  Mortillet  divides  the  prehistoric  period,  as  a 
whole,  into  four  epochs.  The  first  of  these  is  the  preglacial, 
which  he  estimates  as  comprising  seventy-eight  thousand 
years;  the  second  is  the  glacial,  covering  one  hundred  thou- 
sand years;  then  follows  what  he  terms  the  Solutreen,  which 
numbers  eleven  thousand  years;  and,  finally,  the  Magdalenien, 
comprising  thirty-three  thousand  years.  This  gives,  for  the 
prehistoric  period  proper,  a  term  of  about  two  hundred  and 
twenty-two  thousand  years.  Add  to  this  perhaps  twelve 
thousand  years  ushering  in  the  civilization  of  Egypt,  and  the 
six  thousand  years  of  stable,  sure  chronology  of  the  historical 
period,  and  we  have  something  like  two  hundred  and  thirty 
thousand  or  two  hundred  and  forty  thousand  years  as  the 
age  of  man. 

301 


A   HISTORY   OF   SCIENCE 

"These  figures,"  says  Mortillet,  "are  certainly  not  exag- 
gerated. It  is  even  probable  that  they  are  below  the  truth. 
Constantly  new  discoveries  are  being  made  that  tend  to  re- 
move farther  back  the  date  of  man's  appearance."  We  see, 
then,  according  to  this  estimate,  that  about  a  quarter  of  a 
million  years  have  elapsed  since  man  evolved  to  a  state  that 
could  properly  be  called  human.  This  guess  is  as  good  as 
another,  and  it  may  advantageously  be  kept  in  mind,  as  it 
will  enable  us  all  along  to  understand  better  than  we  might 
otherwise  be  able  to  do  the  tremendous  force  of  certain  prej- 
udices and  preconceptions  which  recent  man  inherited  from 
his  prehistoric  ancestor.  Ideas  which  had  passed  current  as 
unquestioned  truths  for  one  hundred  thousand  years  or  so 
are  not  easily  cast  aside. 

In  going  back,  in  imagination,  to  the  beginning  of  the  pre- 
historic period,  we  must  of  course  reflect,  in  accordance  with 
modern  ideas  on  the  subject,  that  there  was  no  year,  no 
millennium  even,  when  it  could  be  said  expressly:  "  This  being 
was  hitherto  a  primate,  he  is  now  a  man."  The  transition 
period  must  have  been  enormously  long,  and  the  changes 
from  generation  to  generation,  even  from  century  to  century, 
must  have  been  very  slight.  In  speaking  of  the  extent  of 
the  age  of  man  this  must  be  borne  in  mind :  it  must  be  recalled 
that,  even  if  the  period  were  not  vague  for  other  reasons,  the 
vagueness  of  its  beginning  must  make  it  indeterminate. 

Bibliographical  Notes. — A  great  mass  of  literature  has  been 
produced  in  recent  years  dealing  with  various  phases  of  the 
history  of  prehistoric  man.  No  single  work  known  to  the 
writer  deals  comprehensively  with  the  scientific  attainments 
of  early  man;  indeed,  the  subject  is  usually  ignored,  except 
where  practical  phases  of  the  mechanical  arts  are  in  question. 
But  of  course  any  attempt  to  consider  the  condition  of  primi- 
tive man  takes  into  account,  by  inference  at  least,  his  knowl- 
edge and  attainments.  Therefore,  most  works  on  anthro- 
pology, ethnology,  and  primitive  culture  may  be  expected  to 
throw  some  light  on  our  present  subject.  Works  dealing  with 
the  social  and  mental  conditions  of  existing  savages  are  also 
of  importance,  since  it  is  now  an  accepted  belief  that  the  an- 
cestors of  civilized  races  evolved  along  similar  lines  and  passed 
through  corresponding  stages  of  nascent  culture.     Herbert 

302 


APPENDIX 

Spencer's  Descriptive  Sociology  presents  an  unequalled  mass 
of  facts  regarding  existing  primitive  races,  but,  unfortunately, 
its  inartistic  method  of  arrangement  makes  it  repellent  to  the 
general  reader.  E.  B.  Tyler's  Primitive  Culture  and  An- 
thropology; Lord  Avebury's  Prehistoric  Times,  The  Origin  of 
Civilization,  and  The  Primitive  Condition  of  Man;  W.  Boyd 
Dawkin's  Cave-Hunting  and  Early  Man  in  Britain;  and  Ed- 
ward Clodd's  Childhood  of  the  World  and  Story  of  Primitive 
Man  are  deservedly  popular.  Paul  Topinard's  Elements 
d' Anthropologic  Generate  is  one  of  the  best-known  and  most 
comprehensive  French  works  on  the  technical  phases  of  an- 
thropology;  but  Mortillet's  he  Prehistorique  has  a  more  popular 
interest,  owing  to  its  chapters  on  primitive  industries,  though 
this  work  also  contains  much  that  is  rather  technical.  Among 
periodicals,  the  Revue  de  VEcole  d' Anthropologic  de  Paris,  pub- 
lished by  the  professors,  treats  of  all  phases  of  anthropology; 
and  the  American  Anthropologist,  edited  by  F.  W.  Hodge  for 
the  American  Anthropological  Association,  and  intended  as 
"a medium  of  communication  between  students  of  all  branches 
of  anthropology,"  contains  much  that  is  of  interest  from  the 
present  stand-point.  The  last-named  journal  devotes  a  good 
deal  of  space  to  Indian  languages. 


CHAPTER  II 

EGYPTIAN    SCIENCE 

1  (p.  34).  Sir  J.  Norman  Lockyer,  The  Dawn  of  Astronomy ; 
a  study  of  the  temple  worship  and  mythology  of  the  ancient 
Egyptians,  London,  1894. 

2  (p.  43).  G.  Maspero,  Histoire  Ancienne  des  Peuples  de 
V Orient  C las sique,  Paris,  1895.  Translated  as  (1)  The  Dawn 
of  Civilization,  (2)  The  Struggle  of  the  Nations,  (3)  The  Passing 
of  the  Empires,  3  vols.,  London  and  New  York,  1 894-1 900. 
Professor  Maspero  is  one  of  the  most  famous  of  living  Orient- 
alists. His  most  important  special  studies  have  to  do  with 
Egyptology,  but  his  writings  cover  the  entire  field  of  Oriental 
antiquity.  He  is  a  notable  stylist,  and  his  works  are  at  once 
readable  and  authoritative. 

3  (p.  44).  Adolf  Erman,   Life  in  Ancient  Egypt,   London, 

3°3 


A   HISTORY   OF   SCIENCE 

1894,  pp.  352.  (Translated  from  the  original  German  work 
entitled  Aegypten  und  aegyptisches  Leben  in  Alterthum,  Tub- 
igen,  1887.)  An  altogether  admirable  work,  full  of  interest 
for  the  general  reader,  though  based  on  the  most  erudite 
studies. 

4  (p.  47)-  Erman,  op.  cit.,  pp.  356,  357. 

6  (p.  48).  Erman,  op.  cit.,  p.  357.  The  work  on  Egyptian 
medicine  here  referred  to  is  Georg  Ebers'  edition  of  an  Egyp- 
tian document  discovered  by  the  explorer  whose  name  it 
bears.  It  remains  the  most  important  source  of  our  knowl- 
edge of  Egyptian  medicine.  As  mentioned  in  the  text,  this 
document  dates  from  the  eighteenth  dynasty — that  is  to  say, 
from  about  the  fifteenth  or  sixteenth  century,  B.C.,  a  relatively 
late  period  of  Egyptian  history. 

6  (p.  49).  Erman,  op.  cit.,  p.  357. 

7  (p.  50).  The  History  of  Herodotus,  II.,  85-90.  There  are 
numerous  translations  of  the  famous  work  of  the  "father  of 
history,"  one  of  the  most  recent  and  authoritative  being  that 
of  G.  C.  Macaulay,  M.A.,  in  two  volumes,  Macmillan  &  Co., 
London  and  New  York,  1890. 

8  (p.  50).  The  Historical  Library  of  Diodorus  the  Sicilian, 
London,  1700.  This  most  famous  of  ancient  world  histories  is 
difficult  to  obtain  in  an  English  version.  The  most  recently 
published  translation  known  to  the  writer  is  that  of  G.  Booth, 
London,  18 14. 

9  (p.  51).  Erman,  op.  cit.,  p.  357. 

10  (p.  52).  The  Papyrus  Rhind  is  a  sort  of  mathematical 
hand-book  of  the  ancient  Egyptians;  it  was  made  in  the 
time  of  the  Hyksos  Kings  (about  2000  B.C.),  but  is  a  copy 
of  an  older  book.  It  is  now  preserved  in  the  British  Mu- 
seum. 

The  most  accessible  recent  sources  of  information  as  to  the 
social  conditions  of  the  ancient  Egyptians  are  the  works  of 
Maspero  and  Erman,  above  mentioned;  and  the  various  pub- 
lications of  W.  M.  Flinders  Petrie,  The  Pyramids  and  Temples 
of  Gizeh,  London,  1883;  Tanis  I.,  London,  1885;  Tanis  II., 
Nebesheh,  and  Defennel,  London,  1887;  Ten  Years'  Diggings, 
London,  1892  ;  Syria  and  Egypt  from  the  J 'el-el- Amarna  Letters, 
London,  1898,  etc.  The  various  works  of  Professor  Petrie, 
recording  his  explorations  from  year  to  year,  give  the  fullest 
available  insight  into  Egyptian  archaeology. 

304 


APPENDIX 

CHAPTER  III 

SCIENCE    OF    BABYLONIA    AND    ASSYRIA 

1  (P-  57)-  The  Medes.  Some  difference  of  opinion  exists 
among  historians  as  to  the  exact  ethnic  relations  of  the  con- 
querors; the  precise  date  of  the  fall  of  Nineveh  is  also  in 
doubt. 

2  (P-  57)-  Darius.  The  familiar  Hebrew  narrative  ascribes 
the  first  Persian  conquest  of  Babylon  to  Darius,  but  inscrip- 
tions of  Cyrus  and  of  Nabonidus,  the  Bab)donian  king,  make 
it  certain  that  Cyrus  was  the  real  conqueror.  These  inscrip- 
tions are  preserved  on  cylinders  of  baked  clay,  of  the  type 
made  familiar  by  the  excavation  of  the  past  fifty  years,  and 
they  are  invaluable  historical  documents. 

3  (p.  58).  Berosus.  The  fragments  of  Berosus  have  been 
translated  by  I.  P.  Cory,  and  included  in  his  Ancient  Frag- 
ments of  Phoenician,  Chaldean,  Egyptian,  and  Other  Writers, 
London,  1826,  second  edition,  1832. 

4  (p.  58).  Chaldean  learning.  Recent  writers  reserve  the 
name  Chaldean  for  the  later  period  of  Babylonian  history — 
the  time  when  the  Creeks  came  in  contact  with  the  Mesopo- 
tamians — in  contradistinction  to  the  earlier  periods  which 
are  revealed  to  us  by  the  archaeological  records. 

5  (p,  59).  King  Sargon  of  Agade.  The  date  given  for  this 
early  king  must  not  be  accepted  as  absolute ;  but  it  is  probably 
approximately  correct. 

6  (p.  59).  Nippur.  See  the  account  of  the  early  expedi- 
tions as  recorded  by  the  director,  Dr.  John  P.  Peters,  Nippur, 
or  explorations  and  adventures,  etc.,  New  York  and  London, 
1897. 

7.  (p.  62).  Fritz  Hommel,  Geschichte  Babyloniens  und  Assy- 
riens,  Berlin,  1885. 

8  (p.  63).  R.  Campbell  Thompson,  Reports  of  the  Magicians 
and  Astrologers  of  Nineveh  and  Babylon,  London,  1900,  p.  xix. 

9  (p.  64).  George  Smith,  The  Assyrian  Canon,  p.  21. 

10  (p.  64).  Thompson,  op.  cit.,  p.  xix. 

11  (p.  65).  Thompson,  op.  cit.,  p.  2. 

12  (p.  67).  Thompson,  op.  cit.,  p.  xvi. 

13  (p.  68).  Sextus  Empiricus,  author  of  Adversus  Mathe- 
maticos,  lived  about  200  a.d. 

VOL.  I.  —  20  30^ 


A    HISTORY   OF   SCIENCE 

14  (p.  68).  R.  Campbell  Thompson,  op.  cit.,  p.  xxiv. 

15  (p.  72).  Records  of  the  Past  (editor,  Samuel  Birch),  vol. 
III.,  p.  139. 

18  (p.  72).  Ibid.,  vol.  V.,  p.  16. 

17  (p.  72).  Quoted  in  Records  of  the  Past,  vol.  III.,  p.  143, 
from  the  Translations  of  the  Society  of  Biblical  Archeology, 
vol.  II.,  p.  58. 

18  (p-  73)-  Records  of  the  Past,  vol.  I.,  p.  131. 

19  (P-  73)-  Ibid.,  vol.  V.,  p.  171. 

20  (p.  74).  Ibid.,  vol.  V.,  p.  169. 

21  (p.  74).  Joachim  Menant,  La  Bibliotheque  du  Palais  de 
Ninive,  Paris,  1880. 

22  (p.  76).  Code  of  Khamurabi.  This  famous  inscription  is 
on  a  block  of  black  diorite  nearly  eight  feet  in  height.  It  was 
discovered  at  Susa  by  the  French  expedition  under  M.  de 
Morgan,  in  December,  1901.  We  quote  the  translation  given 
in  The  Historians'  History  of  the  World,  edited  by  Henry  Smith 
Williams,  London  and  New  York,  1904,  vol.  I.,  p.  510. 

23  (P-  77)-  The  Historical  Library  of  Diodorus  Siculus,  vol. 
I.,  p.  519. 

24  (p.  82).  George  S.  Goodspeed,  Ph.D.,  History  of  the 
Babylonians  and  Assyrians,  New  York,  1902. 

25  (p.  82).  George  Rawlinson,  Great  Oriental  Monarchies 
(second  edition,  London,  1871),  vol.  III.,  pp.  75  ff. 

Of  the  books  mentioned  above,  that  of  Hommel  is  particu- 
larly full  in  reference  to  culture  development;  Goodspeed 's 
small  volume  gives  an  excellent  condensed  account ;  the  orig- 
inal documents  as  translated  in  the  various  volumes  of  Records 
of  the  Past  are  full  of  interest ;  and  Menant's  little  book  is  al- 
together admirable.  The  work  of  excavation  is  still  going  on 
in  old  Babylonia,  and  newly  discovered  texts  add  from  time 
to  time  to  our  knowledge,  but  A.  H.  Layard's  Nineveh  and  its 
Remains  (London,  1849)  s^  has  importance  as  a  record  of 
the  most  important  early  discoveries.  The  general  histories 
of  Antiquity  of  Duncker,  Lenormant,  Maspero,  and  Meyer 
give  full  treatment  of  Babylonian  and  Assyrian  development. 
Special  histories  of  Babylonia  and  Assyria,  in  addition  to  these 
named  above,  are  Tiele's  Babylonisch-Assyrische  Geschichte 
(Zwei  Tiele,  Gotha,  1886-1888);  Winckler's  Geschichte  Baby- 
loniens  und  Assyriens  (Berlin,  188 5 -1888),  and  Rogers'  His- 
tory of  Babylonia  and  Assyria,  New  York  and  London,  1900, 

306 


APPENDIX 

the  last  of  which,  however,  deals  almost  exclusively  with 
political  history.  Certain  phases  of  science,  particularly  with 
reference  to  chronology  and  cosmology,  are  treated  by  Ed- 
ward Meyer  {Geschichte  des  Alterthum,  vol.  I.,  Stuttgart,  1884), 
and  by  P.  Jensen  {Die  Kosmologie  der  Babylonier,  Strassburg, 
1890),  but  no  comprehensive  specific  treatment  of  the  sub- 
ject in  its  entirety  has  yet  been  attempted. 


CHAPTER  IV 

THE  DEVELOPMENT  OF  THE  ALPHABET 

1  (p.  87).  Vicomte  E.  de  Rouge\  Memoir e  stir  I'Origine 
Egyptienne  de  V Alphabet  Phenicien,  Paris,  1874. 

2  (p.  88).  See  the  various  publications  of  Mr.  Arthur  Evans. 

3  (p.  89).  Aztec  and  Maya  writing.  These  pictographs  are 
still  in  the  main  undecipherable,  and  opinions  differ  as  to  the 
exact  stage  of  development  which  they  represent. 

4  (p.  90).  E.  A.  Wallace  Budge's  First  Steps  in  Egyptian, 
London,  1895,  is  an  excellent  elementary  work  on  the  Egyp- 
tian writing.  Professor  Erman's  Egyptian  Grammar,  Lon- 
don, 1894,  is  the  work  of  perhaps  the  foremost  living  Egyp- 
tologist. 

5  (P-  93)-  Extant  examples  of  Babylonian  and  Assyrian 
writing  give  opportunity  to  compare  earlier  and  later  systems, 
so  the  fact  of  evolution  from  the  pictorial  to  the  phonetic 
system  rests  on  something  more  than  mere  theory. 

6  (p.  96).  Friedrich  Delitzsch,  Assyrische  Lesestucke  mit 
grammatischen  Tabellen  und  vollstdndigem  Glossar  einfuhntng 
in  die  assyrische  und  babylonische  Keilschrijt  -  litteratur  bis 
hinauf  zu  Hammurabi,  Leipzig,  1900. 

7  (p.  97).  It  does  not  appear  that  the  Babylonians  them- 
selves ever  gave  up  the  old  system  of  writing,  so  long  as  they 
retained  political  autonomy. 

8  (p.  101).  See  Isaac  Taylor's  History  of  the  Alphabet;  an 
Account  of  the  Origin  and  Development  of  Letters,  new  edition, 
2  vols.,  London,  1899. 

For  fac-sirniles  of  the  various  scripts,  see  Henry  Smith 
Williams'  History  of  the  Art  of  V/riting,  4  vols,  New  York  and 
London,  1902-1903. 

3°7 


A    HISTORY    OF   SCIENCE 
CHAPTER  V 

THE    BEGINNINGS    OF    GREEK    SCIENCE 

1  (p.  in).  Anaximander,  as  recorded  by  Plutarch,  Symp. 
VIII. ,  730E.  See  Arthur  Fairbanks'  First  Philosophers  of  Greece: 
an  Edition  and  Translation  of  the  Remaining  Fragments  of  the 
Pre-Socratic  Philosophers,  together  with  a  Translation  of  the  more 
Important  Accounts  of  their  Opinions  Contained  in  the  Early 
Epitomes  of  their  Works,  London,  1898.  This  highly  scholarly 
and  extremely  useful  book  contains  the  Greek  text  as  well  as 
translations. 

CHAPTER  VI 


THE    EARLY    GREEK    PHILOSOPHERS    IN    ITALY 

1  (p.  117).  George  Henry  Lewes,  A  Biographical  History  of 
Philosophy  from  its  Origin  in  Greece  down  to  the  Present  Day, 
enlarged  edition,  New  York,  1888,  p.  17. 

2  (p.  121).  Diogenes  Laertius,   The  Lives  and  Opinions  of 
Eminent  Philosophers,    C.    D.   Yonge's  translation,   London 
1853,  VIII.,  15. 

3  (p.  121).  Alexander,  Successions  of  Philosophers. 

4  (p.  122).  "All  over  its  centre."  Presumably  this  is  in- 
tended to  refer  to  the  entire  equatorial  region. 

5  (p.  125).  Laertius,  op.  cit.,  pp.  348-351. 

6  (p.  128).  Arthur  Fairbanks,  The  First  Philosophers  of 
Greece,  London,  1898,  pp.  67-71. 

7  (p.  129).  Ibid.,  p.  8^. 

8  (p.  130).  Ibid.,  p.  109. 

9  (p.  131).  Heinrich  Ritter,  The  History  of  Ancient  Philos- 
ophy, translated  from  the  German  by  A.  J.  W.  Morrison,  4 
vols.,  London,  1838,  vol,  I.,  p.  463. 


10  (P 

11  (P 

12  (P 

13  (P 

14  (P 

15  (P 

16  (P 
»  (p 


131).  Ibid.,  p.  465. 

132).  George  Henry  Lewes,  op.  cit.,  p.  51. 

135).  Fairbanks,  op.  cit.,  p.  201. 

136).  Ibid.,  p.  234. 

137).  Ibid., 

137).  Ibid., 


138).  Ibid. 
138).  Ibid. 


191 


308 


APPENDIX 

CHAPTER  VII 

GREEK   SCIENCE    IN   THE    EARLY    ATTIC    PERIOD 

1  (p.  150).  Theodor  Gomperz,  Greek  Thinkers:  a  History  of 
Ancient  Philosophy  (translated  from  the  German  by  Laurie 
Magnes),  New  York,  1901,  pp.  220,  221. 

1  (P-  153)-  Aristotle's  Treatise  on  Respiration,  ch.  ii. 

3  (p.  159).  Fairbanks'  translation  of  the  fragments  of  An- 
axagoras,  in  The  First  Philosophers  of  Greece,  pp.  239-243. 

CHAPTER  VIII 

POST-SOCRATIC    SCIENCE    AT   ATHENS 

1  (p.  180).  Alfred  William  Benn,  The  Philosophy  of  Greece 
Considered  in  Relation  to  the  Character  and  History  of  its  People, 
London,  1898,  p.  186. 

2  (p.  183).  Aristotle,  quoted  in  William  Whewell's  History 
of  the  Inductive  Sciences  (second  edition,  London,  1847),  v°l« 
II.,  p.  161. 

CHAPTER  IX 

GREEK  SCIENCE  OF  THE  ALEXANDRIAN  OR  HELLENISTIC  PERIOD 

1  (p.  195).  Tertullian's  Apologeticus. 

2  (p.  205).  We  quote  the  quaint  old  translation  of  North, 
printed  in  1657. 

CHAPTER  X 

SCIENCE    OF    THE    ROMAN    PERIOD 

1  (p.  258).  The  Geography  of  Strabo,  translated  by  H.  C.  Ham- 
ilton and  W.  Falconer,  3  vols.  London,  1857,  vol.  I.,  pp.  19,  20. 

2  (p.  260).  Ibid.,  p.  154. 

3  (p.  263).  Ibid.,  pp.  169,  170. 
*  (p.  264).  Ibid.,  pp.  166,  167. 

5  (p.  271).  K.  O.  Miller  and  John  W.  Donaldson,  The  His- 
tory of  the  Literature  of  Greece,  3  vols.,  London,  vol.  III.,  p. 
268. 

309 


A   HISTORY   OF   SCIENCE 

8  (p.  276).  E.  T.  Withington,  Medical  History  from  the  Ear- 
liest Times,  London,  1894,  p.  118. 

7  (p.  281).  Ibid. 

8  (p.  281).  Johann   Hermann   Bass,   History   of  Medicine, 
New  York,  1889. 


CHAPTER  XI 

A   RETROSPECTIVE   GLANCE   AT   CLASSICAL   SCIENCE 

1  (p.  298).  Dion  Cassius,  as  preserved  by  Xiphilinus.  Our 
extract  is  quoted  from  the  translation  given  in  The  Histori- 
ans' History  of  the  World  (edited  by  Henry  Smith  Williams), 
25  vols.,  London  and  New  York,  1904,  vol.  VI.,  p.  297  ff. 

[For  further  bibliographical  notes,  the  reader  is  referred  to 
the  Appendix  of  volume  V.] 


END   OF   VOL.  I 


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